Adrenal tumors treated by adrenalectomy following spontaneous rupture carry an overall favorable prognosis: retrospective evaluation of outcomes in 59 dogs and 3 cats (2000–2021)

Marine Traverson Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC

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Junxian Zheng Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC
Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY

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Giovanni Tremolada Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO

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Carolyn L. Chen Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH

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Megan Cray Angell Animal Medical Center, Boston, MA

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William T. N. Culp Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California-Davis, Davis, CA

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Erin A. Gibson Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California-Davis, Davis, CA

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Michelle L. Oblak Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada

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Vanna M. Dickerson Department of Small Animal Clinical Sciences, School of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX

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Daniel J. Lopez Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY

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Elizabeth A. Maxwell Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL

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Pierre Ansellem Department of Veterinary Clinical Sciences, College of Veterinary Medicine, University of Minnesota, Saint Paul, MN

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Owen T. Skinner Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Columbia, MO

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Laura E. Selmic Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH

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Abstract

OBJECTIVE

To conduct a retrospective multi-institutional study reporting short- and long-term outcomes of adrenalectomy in patients presenting with acute hemorrhage secondary to spontaneous adrenal rupture.

ANIMALS

59 dogs and 3 cats.

METHODS

Medical records of dogs and cats undergoing adrenalectomy between 2000 and 2021 for ruptured adrenal masses were reviewed. Data collected included clinical presentation, preoperative diagnostics, surgical report, anesthesia and hospitalization findings, histopathology, adjuvant treatments, and long-term outcome (recurrence, metastasis, and survival).

RESULTS

Median time from hospital admission to surgery was 3 days, with 34% of surgeries being performed emergently (within 1 day of presentation). Need for intraoperative blood transfusion was significantly associated with emergent surgery and presence of active intraoperative hemorrhage. The short-term (≤ 14 days) complication and mortality rates were 42% and 21%, respectively. Negative prognostic factors for short-term survival included emergent surgery, intraoperative hypotension, and performing additional surgical procedures. Diagnoses included adrenocortical neoplasia (malignant [41%], benign [12%], and undetermined [5%]), pheochromocytoma (38%), a single case of adrenal fibrosis and hemorrhage (2%), and a single case of hemangiosarcoma (2%). Local recurrence and metastasis of adrenocortical carcinoma were confirmed in 1 and 3 cases, respectively. Overall median survival time was 574 days and 900 days when short-term mortality was censored. No significant relationship was found between histopathological diagnosis and survival.

CLINICAL RELEVANCE

Adrenalectomy for ruptured adrenal gland masses was associated with similar short- and long-term outcomes as compared with previously reported nonruptured cases. If hemodynamic stability can be achieved, delaying surgery and limiting additional procedures appear indicated to optimize short-term survival.

Abstract

OBJECTIVE

To conduct a retrospective multi-institutional study reporting short- and long-term outcomes of adrenalectomy in patients presenting with acute hemorrhage secondary to spontaneous adrenal rupture.

ANIMALS

59 dogs and 3 cats.

METHODS

Medical records of dogs and cats undergoing adrenalectomy between 2000 and 2021 for ruptured adrenal masses were reviewed. Data collected included clinical presentation, preoperative diagnostics, surgical report, anesthesia and hospitalization findings, histopathology, adjuvant treatments, and long-term outcome (recurrence, metastasis, and survival).

RESULTS

Median time from hospital admission to surgery was 3 days, with 34% of surgeries being performed emergently (within 1 day of presentation). Need for intraoperative blood transfusion was significantly associated with emergent surgery and presence of active intraoperative hemorrhage. The short-term (≤ 14 days) complication and mortality rates were 42% and 21%, respectively. Negative prognostic factors for short-term survival included emergent surgery, intraoperative hypotension, and performing additional surgical procedures. Diagnoses included adrenocortical neoplasia (malignant [41%], benign [12%], and undetermined [5%]), pheochromocytoma (38%), a single case of adrenal fibrosis and hemorrhage (2%), and a single case of hemangiosarcoma (2%). Local recurrence and metastasis of adrenocortical carcinoma were confirmed in 1 and 3 cases, respectively. Overall median survival time was 574 days and 900 days when short-term mortality was censored. No significant relationship was found between histopathological diagnosis and survival.

CLINICAL RELEVANCE

Adrenalectomy for ruptured adrenal gland masses was associated with similar short- and long-term outcomes as compared with previously reported nonruptured cases. If hemodynamic stability can be achieved, delaying surgery and limiting additional procedures appear indicated to optimize short-term survival.

Introduction

Primary adrenal tumors account for < 2% and about 0.2% of canine and feline neoplasia, respectively.1 Adrenalectomy has been associated with an overall favorable long-term outcome regardless of the benign or malignant nature of the disease process,26 with median survival times (MSTs) ranging from 270 to 844 days and low rates of recurrence (0% to 22%)5,710 and metastasis (5% to 24%).912 Perioperative morbidity remains generally high, with reported mortality rates ranging from 4.2% to 43% depending on the selected population.3,6,9,11,1315

Multiple retrospective studies28,1116 have described the outcome for specific tumor types, sizes, anatomic configurations, clinical presentations, or surgical approaches. However, only a few case reports and case series1722 describe the outcome of dogs presenting with extracapsular adrenal gland hemorrhage secondary to spontaneous adrenal tumor rupture. The perioperative mortality rate has been reported as high as 50%,6,17 and studies have suggested that dogs with extracapsular adrenal gland hemorrhage are prone to developing arrhythmias, hypotension, and postoperative complications as well as requiring a blood transfusion and having an overall longer duration of hospitalization compared with nonruptured cases.6 Little information is available regarding their prognostic factors and long-term outcome.

The purpose of this retrospective study was to describe the short- and long-term outcomes of dogs and cats undergoing adrenalectomy for the treatment of adrenal gland tumors with extracapsular hemorrhage secondary to nontraumatic rupture. Particular attention was paid to the timing of the surgical procedure and its association with short-term survival rate. Primary variables considered for long-term outcomes were survival, rate of local recurrence, and metastasis. The authors hypothesized that initial stabilization and delayed surgical procedure would be associated with increased short-term survival over emergent surgical management and that the tumor’s recurrence and metastasis rates would be low.

Methods

Case selection

The medical records from 10 academic institutions and 1 private referral institution were searched to identify dogs and cats of any age, body weight, reproductive status, sex, and breed with primary adrenal tumors that underwent adrenalectomy between January 1, 2000, and June 1, 2021. The inclusion criteria consisted of dogs and cats that were taken to surgery for an adrenalectomy after presenting with a spontaneously ruptured adrenal mass as suspected by the presence of retroperitoneal effusion, peritoneal effusion or hematoma detected on preoperative imaging, and with the effusion confirmed as blood by abdominocentesis (PCV ≥ 20%) or during surgery. No minimum follow-up duration was required considering the rarity of the presentation. Cases were excluded from the analysis if spontaneous hemorrhagic effusion or hematoma could not be confirmed after review of the laboratory diagnostics, imaging, and/or surgery reports.

Data collection

Data extracted from medical records included signalment; history; clinical presentation; preoperative blood work; coagulation panels; adrenal function test results; abdominal fluid analysis results; blood pressure (BP) readings; electrocardiogram findings; preoperative management and response to treatment; diagnostic imaging; surgical, histopathological, anesthesia, and postoperative findings; adjuvant treatment; and long-term follow-up and survival.

Preoperative diagnostic imaging results were reviewed to record tumor lateralization, size, presence of retroperitoneal and/or peritoneal fluid, hematoma, evidence of vascular and/or surrounding tissue tumor invasion, and suspicion for metastasis. Time-interval between initial presentation and surgery, gross tumor findings, active hemorrhage, caval venotomy, ureteronephrectomy, other surgical procedures, intraoperative complications and management, and surgery and anesthesia durations were recorded. An emergent procedure was defined as a time interval of ≤ 1 day between presentation and surgery. Intraoperative hypotension (defined as a mean arterial pressure < 60 mm Hg or a systolic BP < 80 mm Hg for ≥ 10 minutes), hypertension (defined as a systolic BP ≥ 180 mm Hg for ≥ 10 minutes), major intraoperative hemorrhage (defined as requiring a blood transfusion and/or recorded as significant by the surgeon), blood products received, and cardiac arrhythmia and associated treatment were recorded. Information retrieved from the histopathology report included diagnosis and confirmed metastatic disease of any organ sampled. Postoperative complications and treatments associated, total duration of hospitalization, and short-term survival (≤ 14 days postoperatively) were recorded. Medical records from the referring veterinarian and/or referral institutions were collected to gain information regarding long-term follow-up examination and diagnostics, evidence and date of local recurrence and/or metastasis, adjuvant treatments and potential complications, and overall survival time. Owners were contacted as needed to confirm the dog or cat survival status or date of death, the cause of death, and necropsy results if indicated.

Statistical analysis

Associations between continuous variables and binary variables were examined via Wilcoxon rank sum tests. Associations between binary variables were examined via the Fisher exact test. Associations of postoperative complications, short-term survival, and duration of hospitalization with preoperative blood work abnormalities were done with a series of Bonferroni-corrected Fisher exact tests and the Wilcoxon rank sum test. Associations between continuous variables and long-term survival were examined with univariate Cox proportional hazards models. Overall and censored (excluding short-term mortality) MSTs were estimated across the entire study population, including dogs and cats lost to follow-up and alive at the time of study completion, and illustrated in Prism 9 (GraphPad) using a Kaplan-Meier analysis. The cause of death was not restricted to the adrenal disease in the survival analysis due to the absence of consistent necropsy. A cutoff value of 0.05 was used for significance.

Results

Clinical presentation

Fifty-nine dogs and 3 cats met the inclusion criteria. Clinical signs at presentation included lethargy (40/62 [64.5%]), abdominal pain (15/62 [24.2%]), collapse (13/62 [21.0%]), pale mucous membranes (12/62 [19.3%]), panting or tachypnea (10/62 [16.1%]), hyporexia (8/62 [12.9%]), abdominal distension (7/62 [11.3%]), vomiting (6/62 [9.7%]), restlessness (5/62 [8.0%]), shaking or trembling (4/62 [6.5%]), and back pain (1/62 [1.6%]). Additionally, 14 of 62 (22.6%) dogs and cats were presented with urinary signs of varied chronicity. Cranial organomegaly was reported in 4 of 62 (6.5%) cases on physical examination. In 4 of 62 (6.5%) cases, the adrenal mass was found incidentally via ultrasonography (n = 1 dog) or tomodensitometry (3 dogs). The population’s demographics and clinical presentation were summarized (Table 1).

Table 1

Population demographics and clinical presentation.

Variables Species
Dogs Cats
Breeds represented (n)
 Crossbreed 12
 Labrador Retriever 8
 Golden Retriever 7
 German Shepherd Dogs 5
 Beagle 4
 Boxer 2
 Yorkshire Terrier 2
 Fox Terrier 1
 Bichon Frise 1
 Glen of Imaal Terrier 1
 Labradoodle 1
 Soft-Coated Wheaten Terrier 1
 Basenji 1
 American Eskimo 1
 American Cocker Spaniel 1
 Doberman Pinscher 1
 Standard Poodle 1
 Rhodesian Ridgeback 1
 Australian Blue Heeler 1
 Collie 1
 Anatolian Shepherd 1
 Border Terrier 1
 Bassett Hound 1
 Boston Terrier 1
 Cavalier King Charles Spaniel 1
 Pit bull–type dog 1
 Domestic shorthair 3
Sex status
 Spayed females 29 1
 Castrated males 28 2
 Intact female 1
 Intact male 1
Median age (y) 11 (range, 5–13) 8.4 (range, 8.2–12.9)
Median body weight (kg) 26.8 (range, 5.1–63.9; 23/59 [38.9%] ≤ 20 kg) 5.6 (range, 5.5–6.0)
Clinical signs (n)
 Lethargy 37 3
 Abdominal pain 13 2
 Collapse 12 1
 Pale mucous membranes 12
 Panting or tachypnea 9 1
 Hyporexia 6 2
 Abdominal distension 7
 Vomiting 5 1
 Restlessness 4 1
 Shaking or trembling 3 1
 Back pain 1
 Polyuria-polydipsia 12
 Inappropriate urination 2 1
Physical examination findings (n)
 Cranial organomegaly 3 1
 Palpable fluid wave 4

Preoperative diagnostics and treatments

Complete preoperative blood work was performed in 60 of 62 cases. Anemia was evident in 22 of 62 (35.5%) cases, including 2 cats, and thrombocytopenia was reported in 7 of 60 (11.6%) canine cases, with 2 of 7 dogs that had a confirmed platelet count < 100 × 103/µL (41 and 82 × 103/µL). Overall median peripheral PCV was 38% (range, 17.3% to 57%) in dogs and 30% (range, 23% to 37%) in cats. Abdominocentesis was performed in 18 of 62 (29.0%) canine cases and diagnostic of hemorrhagic peritoneal effusion with a median PCV value of 41% (range, 25% to 58%). There was an increased prothrombin and/or partial thromboplastin times ≥ 1.5 times the upper range limit in 7 of 48 (14.6%) canine cases. A hypercoagulable state was suggested via thromboelastography in 4 of 4 (100%) dogs; elevated fibrinogen in 12 of 17 (70.6%) cases, including 1 cat; and elevated D-dimers in 4 of 9 (44.4%) dogs. Only 1 dog out of 45 dogs and cats for which noninvasive BP was measured appeared hypotensive on presentation. Seven dogs and 2 cats (14.5%) were administrated packed RBCs (pRBCs), and 2 (3.2%) dogs received a whole blood transfusion preoperatively. Lower PCV (P = .001) and platelet count (P = .047) were significantly associated with preoperative blood transfusion.

Adrenal function tests were performed in 26 of 62 (42.1%) cases, including a low-dose dexamethasone suppression test (n = 11 dogs and 1 cat), ACTH stimulation test (11 dogs), urine cortisol-to-creatinine ratio (8 dogs and 1 cat), serum or urine metanephrine (6 dogs), endogenous ACTH (4 dogs), and endogenous steroid hormone levels (1 cat). A primary cortisol-secreting adrenal tumor was suspected in 8 of 21 (38.1%) cases tested for hyperadrenocorticism, and 1 of 8 dogs received preoperative oral trilostane at 1.4 mg/kg once daily (for an unknown duration). A pheochromocytoma was suspected in 20 of 62 (32.2%) canine cases based on adrenal function test (n = 8), systemic hypertension (12), vascular invasion (5), cardiac arrhythmia (2), and/or syncopal episode (1). α-Blockers were administrated preoperatively in 27 of 62 (43.5%) canine cases; 25 dogs received phenoxybenzamine at a mean oral dose of 0.47 mg/kg twice daily (range, 0.085 to 1.4 mg/kg) for a mean duration of 9.2 days (range, 2 to 34 days), and 2 dogs received prazosin at a mean total oral daily dose of 0.38 mg/kg for 12 and 23 days. Phenoxybenzamine use was not associated with the diagnosis of pheochromocytoma (P = .136) but was associated with a nonemergent surgery (P = .016). Other specific preoperative medications in dogs included amlodipine (n = 2), aminocaproic acid (2), diltiazem (1), and heparin at a rate of 10/IU/kg/h (1). There was no specific pretreatment administered in cats.

Fifty-nine of 62 (95.2%) dogs and cats had imaging with abdominal ultrasonography (n = 19 dogs and 1 cat), CT (6 dogs), or a combination of both (31 dogs and 2 cats) preoperatively. Three dogs did not have comprehensive abdominal imaging but had evidence of free fluid on FAST (focused assessment with sonography for trauma) scan, which was confirmed as hemorrhagic on abdominocentesis in 2 of 3. Of the 62 cases that received complete abdominal imaging and/or a FAST scan, peritoneal effusion was noted in 29 dogs (46.7%), retroperitoneal effusion was noted in 39 dogs and 1 cat (64.5%), and both were noted in 16 dogs and 1 cat (27.4%). A retroperitoneal hematoma was suspected in 34 of 59 (57.6%) cases that had complete abdominal imaging, including 1 cat. Other significant imaging findings included splenic (n = 10 dogs) and hepatic nodular lesions (8 dogs), gastric and intestinal foreign bodies (2 dogs), urocystoliths (1 dog), and diffuse small intestinal layer changes (1 cat). Three dogs of 57 (5.2%) dogs and cats that received thoracic imaging preoperatively had suspected pulmonary metastasis (none sampled), and 1 dog had a right caudal lung lobe mass.

Surgical procedure

The overall median time between presentation and surgery in dogs and cats was 3 days (range, 0 to 210 days), with 21 of 62 (33.9%) surgical procedures performed emergently (n = 20 dogs and 1 cat). No significant relationship was found between surgery timing and peripheral PCV (P = .317), lactate (P = .153), platelet count (P = .383), prothrombin time (P = .453), partial thromboplastin time (P = 1), systolic BP (P = .169), and imaging identification of peritoneal effusion (P = .128), retroperitoneal effusion (P = .82), and/or hematoma (P = .053) on presentation. Surgical approach consisted of ventral midline celiotomy (n = 57 dogs and 3 cats), right paracostal approach (1 dog), or combined approach (1 dog). Active adrenal hemorrhage was noted in 15 of 62 (24.1%) cases, including 1 cat. Vascular invasion was confirmed in 15 of 62 (24.1%) canine cases, with a tumor thrombus invading the caudal vena cava (n = 10), phrenicoabdominal (4), and renal (1) vein. Cases with right-sided tumors (n = 28 dogs) had odds of vascular or surrounding tissue invasion that were 2.8 times as high as those in left-sided tumors (30 dogs and 3 cats; OR, 3.35; 95% CI, 1.04 to 10.93; P = .047). Retroperitoneal hematoma (n = 39 dogs and 2 cats), adrenal gland disruption (29 dogs and 1 cat), and tumor adhesions to the ipsilateral kidney (8 dogs) or hypaxial musculature (1 dog) were documented at surgery.

Left, right, and bilateral adrenalectomy were completed in 33 of 62 (53.2%), 28 of 62 (45.2%), and 1 of 62 (1.6%) cases, respectively. Caval venotomy was performed in 10 (16.1%) dogs to retrieve a tumor thrombus, and 12 (19.4%) dogs underwent an ipsilateral ureteronephrectomy. The retroperitoneal hematoma was reportedly removed in 13 (21.3%) dogs and a nephropexy performed in 4 (6.5%) dogs. Additional procedures included liver biopsy (n = 20 dogs), splenectomy (9 dogs), abdominal lymph node extirpation (3 dogs and 1 cat), gastrointestinal biopsy (3 dogs and 1 cat), liver lobectomy (3 dogs), omental nodule excision (2 dogs), gastrotomy (3 dogs), pancreatic nodule excision (1 dog), lung lobectomy (1 dog), typhlectomy (1 dog), renal biopsy (1 dog), cystotomy (1 dog), gastropexy (1 dog), ovariohysterectomy (1 dog), pancreatic and mesenteric nodule excision (1 dog), and excisional biopsy of skin tag (1 dog), perianal mass (1 dog), and facial mass (1 dog).

Thirty-seven of 62 (59.6%) dogs and cats experienced adverse events during anesthesia, including hypotension in 23 dogs and 3 cats (41.9%), hypertension in 5 dogs and 1 cat (9.6%), and cardiac arrhythmia in 16 dogs (25.8%). There was no significant impact of phenoxybenzamine pretreatment on the occurrence of hypotension, hypertension, or cardiac arrhythmia, whether this was considered for the entire study population (P = .566, P = 1, and P = .088, respectively) or pheochromocytoma cases exclusively, according to histopathology (P = .203, P = 1, and P = 1, respectively). Intraoperative hemorrhage upon dissection of the adrenal gland was reported in 22 of 54 (40.7%) canine cases, with major hemorrhage recorded in 8 of 22 (36.3%) dogs. Nineteen of 62 (30.6%) dogs and cats received intraoperative blood transfusions, including pRBCs (n = 16 dogs and 1 cat), fresh frozen plasma (2 dogs), and whole blood (1 dog). In 3 dogs and 1 cat, the transfusion was continued from before the operation. Factors associated with intraoperative transfusion are illustrated (Table 2).

Table 2

Predictive factors of intraoperative blood transfusion.

Variables No. of patients Intraoperative blood transfusion P value, Fisher exact test
Timing of surgerya Emergent 21 10/21 (47.6%) .002
Delayed 41 9/41 (21.9%)
Intraoperative hemorrhage Yes 22 12/22 (54.5%) .003
No 32 5/32 (15.6%)

aTime from presentation to emergent surgery of ≤ 1 day versus median time of 7 days (range, 2 to 210 days) for delayed surgery.

The overall median duration of the surgical procedure and anesthesia was 120 minutes (range, 60 to 350 minutes) and 210 minutes (range, 113 to 480 minutes), respectively. Shorter procedures were significantly associated with emergent surgery and absence of vascular invasion (P < .001 and P = .034, respectively). Overall, 57 dogs and 3 cats (96.7%) recovered from surgery and anesthesia. One dog was euthanized intraoperatively due to uncontrolled adrenal hemorrhage. The second remained comatose postoperatively after an episode of cardiopulmonary arrest and was eventually euthanized. Both underwent surgery within 1 day of presentation.

Postoperative period

Of the 60 cases that survived the surgical procedure, 14 dogs and 2 cats (26.6%) received a blood transfusion postoperatively, including pRBCs (n = 11 dogs and 2 cats), fresh frozen plasma (4 dogs), and whole blood (1 dog); in 6 dogs and 1 cat, the transfusion was continued from intraoperative administration. Twenty-three of 60 (38.3%) dogs and cats received glucocorticoid treatment immediately before and/or after surgery in the form of injectable dexamethasone sodium phosphate (n = 20 dogs and 1 cat) and/or prednisone (15 dogs) or prednisolone (1 cat). For 15 dogs, hypoadrenocorticism was confirmed postoperatively, and 9 continued long-term glucocorticoid treatment (> 14 days postoperatively).

Postoperative complications were reported in 25 of 60 (41.6%) cases, including acute kidney injury (AKI; n = 7 dogs), aspiration pneumonia (5 dogs), disseminated intravascular coagulation (5 dogs), hemoperitoneum (3 dogs), suspected pulmonary thromboembolism (2 dogs), suspected pancreatitis (2 dogs), neurologic signs including seizures (2 dogs), cardiovascular complications such as cardiac arrhythmias (3 dogs), hypo- (3 dogs) or hypertension (1 dog), and tachycardia (2 dog). Of the 7 dogs that developed an AKI, 5 of 7 had a ureteronephrectomy and 3 of 7 developed other postoperative complications, including aspiration pneumonia (n = 2), suspected pancreatitis (1), hemoperitoneum (1), and seizure (1) leading to their death (1) or euthanasia (2). A significant association was noted between ureteronephrectomy and postoperative AKI (P = .003), but not with other variables, including intraoperative hypotension (P = .672). Additionally, there was no significant association between intraoperative hypotension and postoperative AKI within the subpopulation that underwent a ureteronephrectomy (P = .222).

Overall, postoperative complications led to death or euthanasia in 4 and 7 dogs, respectively, with an overall short-term mortality rate of 20.9% (13/62). Median duration of hospitalization was 2 days (range, 1 to 7 days), and 46 dogs and 3 cats survived the postoperative period. There was no significant impact of phenoxybenzamine pretreatment (P = .326 for the entire study population, P = .347 for pheochromocytoma exclusively), ureteronephrectomy (P = .107), postoperative AKI (P = .125), and overall postoperative complications (P = .504) on short-term survival. Variables significantly associated with postoperative AKI and short-term mortality are reported (Tables 3 and 4).

Table 3

Positive association between ureteronephrectomy and postoperative acute kidney injury (≤ 14 days postoperatively).

Prognostic factors No. of patients Postoperative acute kidney injury P value, Fisher exact test
Ureteronephrectomy Yes 12 5/12 (41.6%) .003
No 48 2/48 (4.2%)
Table 4

Predictive factors of short-term mortality (≤ 14 days postoperatively).

Prognostic factors No. of patients Short-term mortality P value, Fisher exact test
Timing of surgerya Emergentb 21 6/21 (28.5%) .015
Delayed 41 7/41 (17.0%)
Additional surgical procedure Yes 43 13/43 (30.2%) .006
No 19 0 (0%)
Intraoperative hypotension Yes 23 9/23 (39.1%) .011
No 39 4/39 (10.3%)

bWithin the subpopulation receiving an emergent surgery, there was also a significant association between hypotension and short-term mortality (P = .012); this was not true for the subpopulation receiving nonemergent surgery (P = 1).

See Table 2 for remainder of key.

Histopathology results

Histopathology results were available in 60 of 62 (96.7%) cases, and diagnoses included adrenocortical carcinoma (n = 25 dogs [41.7%]), pheochromocytoma (22 dogs and 1 cat [38.3%]), adrenocortical adenoma (6 dogs and 1 cat [11.6%]), undetermined adrenocortical neoplasia (2 dogs and 1 cat [5.0%]), and 1 (1.7%) canine case each of adrenal fibrosis and hemorrhage and of hemangiosarcoma with metastasis to the pancreas and kidney. Histopathology was not submitted for 1 of the 2 dogs euthanized under general anesthesia and could not be found in the medical record system of another dog. In the second case, the surgery report indicated an adrenal mass associated with a 5 × 8-cm hematoma, moderate peritoneal hemorrhagic effusion, and no other significant lesion apart from a small liver nodule. Other concurrent histopathologic diagnoses included hepatocellular carcinoma (n = 2 dogs); splenic, hepatic, and metastatic splenic and hepatic hemangiosarcoma unassociated with a primary adrenal hemangiosarcoma (1 dog each); pulmonary carcinoma; oral melanoma; facial carcinoma with mixed squamous and chondroid differentiation (1 dog each); and small intestinal small cell lymphoma (1 cat).

Long-term follow-up

Thirty-nine of 49 (79.5%) dogs and cats that survived the perioperative period had follow-up examinations, with the last visit reported at a median interval of 100 days (range, 4 to 2,466 days) after surgery. Repeated diagnostics at these appointments included blood work (n = 28 dogs and 2 cats), abdominal imaging (20 dogs and 1 cat), and thoracic imaging (18 dogs and 1 cat). Local recurrence (n = 1 dog) and/or metastasis (3 dogs) of neuroendocrine carcinoma to the omentum, liver, spleen, contralateral adrenal gland, and kidney were confirmed on histopathology in a total of 3 dogs at 314, 490, and 510 days postoperatively, including 1 dog that was initially diagnosed with adrenocortical adenoma. Nonsampled suspected metastasis and/or de novo tumors were reported in 7 other dogs and 1 cat, including suspected hepatic metastasis of splenic hemangiosarcoma (n = 1 dog), novel hepatic mass with liver and pulmonary nodules (1 dog), cranial abdominal mass (1 cat), mesenteric nodules (1 dog), thyroid and pulmonary nodules (1 dog), contralateral adrenal mass with pulmonary nodules (1 dog), urothelial cell carcinoma (1 dog), and metastasis of oral malignant melanoma (1 dog).

Seven of 49 (14.2%) dogs and cats received adjuvant chemotherapy at a median interval of 31 days (range, 10 to 545 days) after surgery. Treatment was targeted toward the adrenal neoplasia in 2 dogs and included doxorubicin therapy for metastatic adrenal hemangiosarcoma (30 mg/m2, IV, 1 dose total) and combination therapy with docetaxel and cyclosporine for metastatic adrenocortical carcinoma (1.625 mg/kg and 5 mg/kg orally, respectively, 2 doses at a 1-week interval). Other adjuvant chemotherapy treatments included doxorubicin (n = 2 dogs), carboplatin (1 cat), vinorelbine (1 dog), and chlorambucil (1 dog) for splenic and/or hepatic hemangiosarcoma, gastrointestinal lymphoma, suspected pulmonary carcinoma, and urothelial cell carcinoma, respectively. No dog or cat underwent adjuvant radiation therapy.

Of the 49 cases that survived the perioperative period, 15 dogs and 2 cats (34.7%) were lost to long-term follow-up. Of the remaining 32 cases, 13 dogs (26.5%) were still alive at the time of data collection, and 18 dogs and 1 cat (38.8%) were deceased, leading to overall and censored MSTs of 574 days and 900 days, respectively (range, 0 to 2,466 and 8 to 2,466 days). Long-term cause of death or euthanasia was suspected related to the adrenal neoplasia in 4 of 19 cases, including 1 cat; unrelated in 9 of 19 cases; and unknown in 6 of 19 cases. Case summary and compared Kaplan-Meier survival estimates by tumor types are presented (Table 5; Figure 1).

Table 5

Clinical summary of study population by tumor type (n = 59).

Adrenal tumor diagnosis Adrenocortical carcinoma Pheochromocytoma Adrenocortical adenoma Undetermined adrenocortical neoplasm Hemangiosarcoma
Study population
 Canine 25 22 6 2 1
 Feline 1 1 1
Preoperative diagnostic imaging
 Median maximum tumor axis (range [cm]) 5.6 (2–11.5) 5.7 (1.8–10) 5.4 (0.8–11) 6.2 (4.5–7.4) 5.2
 Suspected vascular invasion 5/25 (20.0%) 9/23 (40.9%) 3/7 (42.8%) 1/3 (33.3%)
 Peritoneal effusion 12/25 (48.0%) 12/23 (52.1%) 2/7 (28.5%) 1/3 (25.0%) 1/1 (100%)
 Retroperitoneal effusion 16/25 (64.0%) 19/23 (86.0%) 2/7 (28.5%) 3/3 (100%)
 Retroperitoneal hematoma 16/25 (64.0%) 8/23 (36.3%) 4/7 (57.1%) 3/3 (100%) 1/1 (100%)
Preoperative treatment
 Phenoxybenzamine 7/25 (28.0%) 12/23 (52.1%) 4/7 (57.1%) 1/3 (33.3%)
 Blood transfusion 5/25 (20.0%) 2/23 (8.6%) 1/7 (14.3%) 1/3 (33.3%)
Surgical procedure
 Adrenalectomy (L/R) 16/10 10/13 3/4 3 L 1 R
 Caval venotomy 3/25 (12.0%) 7/23 (30.4%)
 Ureteronephrectomy 2/25 (8.0%) 7/23 (30.4%) 1/3 (33.3%) 1/1 (100%)
 Additional procedures 16/25 (64.0%) 15/23 (65.2%) 5/7 (71.4%) 3/3 (100%) 1/1 (100%)
Anesthesia
 Systemic hypotension 11/24 (45.8%) 9/21 (42.8%) 3/7 (42.8%) 1/3 (33.3%)
 Systemic hypertension 2/24 (8.3%) 5/21 (23.8%) 1/3 (33.3%)
 Cardiac arrhythmias 8/24 (33.3%) 5/21 (23.8%) 1/7 (14.3%) 1/1 (100%)
Postoperative period (≤ 14 d)
 Glucocorticoid treatment 14/24 (58.3%) 7/23 (30.4%) 1/7 (14.3%) 1/3 (33.3%)
 Complications 8/24 (33.3%) 14/23 (60.8%) 2/7 (28.5%) 1/1 (100%)
 Short-term mortality 6/24 (25.0%) 6/23 (26.0%)
Long-term follow-up
 Local recurrence 1/19 (5.2%)
 Distant metastasis 2/19 (10.5%) 1/7 (14.3%) 1/1 (100%)
 Targeted adjuvant chemotherapy Docetaxel and cyclosporine (n = 1) Doxorubicin (n = 1)
 Targeted adjuvant radiation therapy
 Median or overall survival time (d) 555 (0–1,443) 580 (1–2,466) 490 (17–987) 942 (479–1,150) 190
 Censoreda median or overall survival time (d) 855 (17–1,443) 1,471 (8–2,466) 490 (17–987) 942 (479–1,150) 190

aExcluding short-term mortality (≤ 14 days postoperatively).

L = Left. R = Right.

Figure 1
Figure 1

Kaplan-Meier survival analysis by tumor type of dogs and cats treated by adrenalectomy for spontaneous adrenal rupture. The survival analysis includes the entire population of dogs and cats diagnosed with either a pheochromocytoma or an adrenocortical tumor (all types confounded) without censoring short-term mortality or cases lost to follow-up. A numerical but statistically nonsignificant difference in median survival time was noted between pheochromocytoma and adrenocortical tumors (P = .583).

Citation: Journal of the American Veterinary Medical Association 261, 12; 10.2460/javma.23.06.0324

Discussion

This study investigated a unique population of dogs and cats presenting with acute spontaneous adrenal hemorrhage and demonstrated that, in this cohort, a delayed surgical treatment was superior to emergent surgical treatment. Additionally, local recurrence and metastasis appeared to occur rarely.

The results confirmed our clinical impression that medical management may allow for acute hemostatic control, potentially because of the enclosed nature of the retroperitoneal space. Interestingly, some dogs and cats presenting with peritoneal effusion also responded favorably to initial conservative treatment despite the larger spaced cavity. Therefore, if cardiovascular stabilization can be achieved, results of the study suggested the procedure should be delayed, which might allow for improved surgical visibility and hemodynamic control. Most previous case reports6,17,18,2022 include dogs receiving emergent surgical stabilization due to cardiovascular decline despite medical management. A guarded outcome with a 50% perioperative mortality rate was also reported for 8 dogs receiving emergent adrenalectomy.6 Overall, limitations in anesthesia, critical care, and surgical support on emergency may play a role in the poorer outcome. It is also possible that cases selected for emergent surgery were more unstable on presentation in our cohort. However, the absence of association between surgery timing and preoperative peripheral PCV, lactate, platelet count, coagulation parameters, BP, or imaging evidence of rupture seems to indicate that the decision to perform the procedure on an emergent basis would rather have been related to institution and/or surgeon preferences. The retrospective nature of the study precludes further conclusion regarding the clinical reasoning behind this surgical decision. The ideal timeline at which surgery should occur remains unclear, and the present study along with our clinical impression seems to suggest that a few days to a week would suffice. Finally, the study reinforces the importance of preoperative diagnostic imaging in identifying the source of hemorrhage in cases of hemoperitoneum, and adapting surgical timing and preparation accordingly.

Spontaneous adrenal tumor rupture is also a rare condition in human medicine, and reported mortality rates of 45% for emergent adrenalectomy have led to delayed surgical treatment when hemodynamic stability can be achieved.23 Marti et al23 established a treatment algorithm based on a patient’s hemodynamic stability and endocrine testing and recommended interval imaging at 3 and 6 months to monitor hematoma resolution and allow time for inflammation to subside. Emphasis on patient stabilization and pretreatment appears critical in cases of functional tumors. In selected cases of nonfunctional tumor, adrenalectomy might ultimately not be elected.23 Additionally, arterial embolization is frequently implemented preoperatively to help control hemostasis, with success rates of up to 82% reported in the acute settings.24 It has also shown satisfactory efficacy as the sole treatment for inoperable tumors or to obtain tumor size reduction, functional resolution, and alleviate pain with no serious adverse reactions.25 Case reports26,27 of arterial embolization demonstrate effective hemodynamic stabilization of veterinary patients presented with continuous epistaxis or hemoperitoneum secondary to ruptured liver mass. However, its use remains anecdotal in veterinary medicine and has not been investigated to our knowledge in cases of spontaneous adrenal hemorrhage.

Adrenal tumor types represented in the current study were similar to those previously reported for nonruptured cases in dogs and cats, excluding a rare case of primary adrenal hemangiosarcoma. Primary adrenal hemangiosarcoma or angiosarcoma has rarely been reported in human medicine and displays an aggressive behavior and overall poor prognosis28,29 characterized by a high propensity for local recurrence and metastasis. Intraoperative detection of abdominal metastases in this particular case aligns with the general rapid progression of the cancer. Overall, there was a preponderance of adrenocortical (60%) over medullary tumors (36%); this fact corroborates the findings of Lang et al,6 who detail 8 cases of spontaneous adrenal hemorrhage, 7 of which had a tumor of adrenocortical origin. Interestingly, pheochromocytoma has been most commonly associated with adrenal rupture in people23,30; other etiologies include carcinoma, adenoma, and myelolipoma.31 Previous veterinary studies have speculated that tumor size > 2 cm,6,8,24,32 vascular invasion,8 and high percentage necrosis32 could represent underlying predisposing factors of rupture. Mean tumor size on CT was 5.8 cm in the current study, which appears subjectively larger than commonly reported.2,4,8,10 Vascular invasion was documented in 37% of histopathology reports, and percentage necrosis was inconsistently evaluated to support further conclusions. Comparison with a nonruptured adrenal tumor population would be required to investigate predisposing factors of spontaneous adrenal rupture.

Overall, short- and long-term outcomes appeared similar to those previously reported for nonruptured primary adrenal tumors, with a relatively high short-term mortality rate (21%) but low recurrence and metastasis rates leading to prolonged survival with adrenalectomy alone.2,7,9,10,33,34 Few cases underwent adjuvant chemotherapy, considering it is not the standard of care for primary adrenal tumors, and for most cases, treatment was targeted to other tumor sites, which did not allow us to draw clear conclusions regarding its benefit in rare cases of metastasis. Additionally, only 1 case of local recurrence of adrenocortical carcinoma was confirmed histologically and may have been related to diffuse metastatic disease. Although nonsignificant statistically, some distinctions in outcomes were observed between etiologies. An overall higher postoperative complication rate was noted with pheochromocytoma, which has previously been described as a risk factor for short-term mortality.10 Perioperative mortality, however, was not impacted by the tumor type in the present study. Long-term prognosis appeared overall less favorable for adrenocortical tumors, with a higher metastatic rate and shorter MST than pheochromocytoma. This survival trend was shared between malignant, benign, and undetermined adrenocortical tumors, which could challenge the reliability of histopathology to rule out a malignant process. In fact, 1 case of adrenocortical adenoma was later diagnosed with metastatic neuroendocrine carcinoma to the liver based on necropsy and histopathology findings without evidence of another primary neuroendocrine tumor. Overall, the low number of cases and the absence of comprehensive long-term follow-up and necropsy related to the retrospective nature of the study preclude further conclusions in that regard. An association between carcinoma and development of metastasis has previously been reported, with compared MSTs of 360 days versus 953 days for the entire study population.8 Other specific retrospective studies13,35 have documented metastatic rates of up to 36% for dogs that presented with adrenocortical tumors. Similar observations have been made in human medicine, with up to 22% metastatic rate on presentation and an increased risk of local recurrence leading to an overall guarded long-term prognosis with adrenocortical carcinoma.36 Altogether, metastatic rates in the present study remained low compared with those of previous studies,2,7,9,10,33,34 but may have been underestimated owing to the lack of routine necropsy. Size of the tumor, presence of a tumor thrombus, or microscopic metastasis was not associated with survival, in contrast to other studies.3,8,9,33 Finally, although this study includes a mixed population of dogs and cats, the low number of feline cases does not support separate conclusions regarding their outcome.

A significantly lower short-term survival rate (75%) was found in dogs and cats that received additional surgical procedures, compared with those cases strictly limited to adrenalectomy (100%). Other studies9,10 have found concurrent nephrectomy to be a negative prognostic factor with an increased risk of acute renal injury postoperatively. This association was confirmed in this study without impacting the short-term survival. Certain procedures appear inevitable, such as performing a ureteronephrectomy in cases of adhesions to the ipsilateral kidney or addressing a gastrointestinal obstruction via gastrotomy/enterotomy. However, these results along with those reported previously suggest that any additional procedure that could be avoided should be postponed. Additionally, intraoperative hypotension was significantly associated with increased short-term mortality, particularly within the group that received an emergent procedure. Interestingly, no association was found between hypotension and AKI, although this could reflect a type II error. Finally, preoperative phenoxybenzamine administration was not associated with a more favorable immediate outcome, compared with findings in a previously published study.32 This finding of the present study was validated in the entire study population and when cases confirmed as pheochromocytoma on histopathology were selected. The absence of pretreatment in the group that received emergent surgery and had an overall poorer outcome could have induced a bias in the analysis; however, no protective effect was observed in the group that had a delayed procedure and received pretreatment. These findings reinforce ongoing debates regarding the validity of such treatment.9,34

Limitations inherent to this study are related to its retrospective multi-institutional nature, including absence of standardization and incomplete medical records, lack of histopathology and necropsy to confirm metastasis, local recurrence, and cause of death. The role of adjuvant therapy for ruptured adrenal tumors cannot be fully established due to the small number of patients involved, and concurrent neoplasia could have affected survival times.

In conclusion, the findings of the present study did not support the need for emergency adrenalectomy in cases of spontaneous adrenal rupture, and delayed adrenalectomy can be attempted while maximizing patient hemodynamic stability, as preemptive hemostasis might reduce the short-term complication rate. Low reported recurrence and metastatic rates do not provide clear evidence of the need for adjuvant therapy.

Acknowledgments

The authors thank James B. Robertson, biostatistician at the North Carolina State University College of Veterinary Medicine, for his assistance with the statistical analysis.

Disclosures

The authors have nothing to disclose. No AI-assisted technologies were used in the generation of this manuscript.

Funding

The authors have nothing to disclose.

References

  • 1.

    Myers NC III. Adrenal incidentalomas. Diagnostic workup of the incidentally discovered adrenal mass. Vet Clin North Am Small Anim Pract. 1997;27(2):381-399. doi:10.1016/S0195-5616(97)50038-6

    • Search Google Scholar
    • Export Citation
  • 2.

    Anderson CR, Birchard SJ, Powers BE, Belandria GA, Kuntz CA, Withrow SJ. Surgical treatment of adrenocortical tumors: 21 cases (1990-1996). J Am Anim Hosp Assoc. 2001;37(1):93-97. doi:10.5326/15473317-37-1-93

    • Search Google Scholar
    • Export Citation
  • 3.

    Cavalcanti JVJ, Skinner OT, Mayhew PD, Colee JC, Boston SE. Outcome in dogs undergoing adrenalectomy for small adrenal gland tumours without vascular invasion. Vet Comp Oncol. 2020;18(4):599-606. doi:10.1111/vco.12587

    • Search Google Scholar
    • Export Citation
  • 4.

    Daniel G, Mahony OM, Markovich JE, et al. Clinical findings, diagnostics and outcome in 33 cats with adrenal neoplasia (2002-2013). J Feline Med Surg. 2016;18(2):77-84. doi:10.1177/1098612X15572035

    • Search Google Scholar
    • Export Citation
  • 5.

    Mitchell JW, Mayhew PD, Culp WTN, et al. Outcome of laparoscopic adrenalectomy for resection of unilateral noninvasive adrenocortical tumors in 11 cats. Vet Surg. 2017;46(5):714-721. doi:10.1111/vsu.12655

    • Search Google Scholar
    • Export Citation
  • 6.

    Lang JM, Schertel E, Kennedy S, Wilson D, Barnhart M, Danielson B. Elective and emergency surgical management of adrenal gland tumors: 60 cases (1999-2006). J Am Anim Hosp Assoc. 2011;47(6):428-435. doi:10.5326/JAAHA-MS-5669

    • Search Google Scholar
    • Export Citation
  • 7.

    Kyles AE, Feldman EC, De Cock HE, et al. Surgical management of adrenal gland tumors with and without associated tumor thrombi in dogs: 40 cases (1994-2001). J Am Vet Med Assoc. 2003;223(5):654-662. doi:10.2460/javma.2003.223.654

    • Search Google Scholar
    • Export Citation
  • 8.

    Massari F, Nicoli S, Romanelli G, Buracco P, Zini E. Adrenalectomy in dogs with adrenal gland tumors: 52 cases (2002-2008). J Am Vet Med Assoc. 2011;239(2):216-221. doi:10.2460/javma.239.2.216

    • Search Google Scholar
    • Export Citation
  • 9.

    Barrera JS, Bernard F, Ehrhart EJ, Withrow SJ, Monnet E. Evaluation of risk factors for outcome associated with adrenal gland tumors with or without invasion of the caudal vena cava and treated via adrenalectomy in dogs: 86 cases (1993-2009). J Am Vet Med Assoc. 2013;242(12):1715-1721. doi:10.2460/javma.242.12.1715

    • Search Google Scholar
    • Export Citation
  • 10.

    Schwartz P, Kovak JR, Koprowski A, Ludwig LL, Monette S, Bergman PJ. Evaluation of prognostic factors in the surgical treatment of adrenal gland tumors in dogs: 41 cases (1999-2005). J Am Vet Med Assoc. 2008;232(1):77-84. doi:10.2460/javma.232.1.77

    • Search Google Scholar
    • Export Citation
  • 11.

    Barthez PY, Marks SL, Woo J, Feldman EC, Matteucci M. Pheochromocytoma in dogs: 61 cases (1984-1995). J Vet Intern Med. 1997;11(5):272-278. doi:10.1111/j.1939-1676.1997.tb00464.x

    • Search Google Scholar
    • Export Citation
  • 12.

    Gilson SD, Withrow SJ, Orton EC. Surgical treatment of pheochromocytoma: technique, complications, and results in six dogs. Vet Surg. 1994;23(3):195-200. doi:10.1111/j.1532-950X.1994.tb00472.x

    • Search Google Scholar
    • Export Citation
  • 13.

    van Sluijs FJ, Sjollema BE, Voorhout G, van den Ingh TSGAM, Rijnberk A. Results of adrenalectomy in 36 dogs with hyperadrenocorticism caused by adreno-cortical tumour. Vet Q. 1995;17(3):113-116. doi:10.1080/01652176.1995.9694547

    • Search Google Scholar
    • Export Citation
  • 14.

    Knight RC, Lamb CR, Brockman DJ, Lipscomb VJ. Variations in surgical technique for adrenalectomy with caudal vena cava venotomy in 19 dogs. Vet Surg. 2019;48(5):751-759. doi:10.1111/vsu.13168

    • Search Google Scholar
    • Export Citation
  • 15.

    Mayhew PD, Culp WTN, Hunt GB, et al. Comparison of perioperative morbidity and mortality rates in dogs with noninvasive adrenocortical masses undergoing laparoscopic versus open adrenalectomy. J Am Vet Med Assoc. 2014;245(9):1028-1035. doi:10.2460/javma.245.9.1028

    • Search Google Scholar
    • Export Citation
  • 16.

    Cook AK, Spaulding KA, Edwards JF. Clinical findings in dogs with incidental adrenal gland lesions determined by ultrasonography: 151 cases (2007-2010). J Am Vet Med Assoc. 2014;244(10):1181-1185. doi:10.2460/javma.244.10.1181

    • Search Google Scholar
    • Export Citation
  • 17.

    Whittemore JC, Preston CA, Kyles AE, Hardie EM, Feldman EC. Nontraumatic rupture of an adrenal gland tumor causing intra-abdominal or retroperitoneal hemorrhage in four dogs. J Am Vet Med Assoc. 2001;219(3):329-333. doi:10.2460/javma.2001.219.329

    • Search Google Scholar
    • Export Citation
  • 18.

    Williams JE, Hackner SG. Pheochromocytoma presenting as acute retroperitoneal hemorrhage in a dog. J Vet Emerg Crit Care (San Antonio). 2001;11(3):221-227. doi:10.1111/j.1476-4431.2001.tb00087.x

    • Search Google Scholar
    • Export Citation
  • 19.

    Santamarina G, Espino L, Vila M, Lopez M, Alemañ N, Suarez ML. Aortic thromboembolism and retroperitoneal hemorrhage associated with a pheochromocytoma in a dog. J Vet Intern Med. 2003;17(6):917-922. doi:10.1111/j.1939-1676.2003.tb02533.x

    • Search Google Scholar
    • Export Citation
  • 20.

    Kirkwood N, Boland L, Brunel L, Wardman A, Barrs VR. Acute adrenal haemorrhage in two cats with aldosterone-secreting adenocarcinomas. JFMS Open Rep. 2019;5(1):2055116919840828. doi:10.1177/2055116919840828

    • Search Google Scholar
    • Export Citation
  • 21.

    Vandenbergh AG, Voorhout G, van Sluijs FJ, Rijnberk A, van den Ingh TS. Haemorrhage from a canine adrenocortical tumour: a clinical emergency. Vet Rec. 1992;131(23):539-540.

    • Search Google Scholar
    • Export Citation
  • 22.

    Evans K, Hosgood G, Boon GD, Kowalewich N. Hemoperitoneum secondary to traumatic rupture of an adrenal tumor in a dog. J Am Vet Med Assoc. 1991;198(2):278-280.

    • Search Google Scholar
    • Export Citation
  • 23.

    Marti JL, Millet J, Sosa JA, Roman SA, Carling T, Udelsman R. Spontaneous adrenal hemorrhage with associated masses: etiology and management in 6 cases and a review of 133 reported cases. World J Surg. 2012;36(1):75-82. doi:10.1007/s00268-011-1338-6

    • Search Google Scholar
    • Export Citation
  • 24.

    Suyama K, Beppu T, Isiko T, et al. Spontaneous rupture of adrenocortical carcinoma. Am J Surg. 2007;194(1):77-78. doi:10.1016/j.amjsurg.2006.10.028

    • Search Google Scholar
    • Export Citation
  • 25.

    O’Keeffe FN, Carrasco CH, Charnsangavej C, Richli WR, Wallace S. Arterial embolization of adrenal tumors: results in nine cases. AJR Am J Roentgenol. 1988;151(4):819-822. doi:10.2214/ajr.151.4.819

    • Search Google Scholar
    • Export Citation
  • 26.

    Kawamura Y, Itou H, Kida A, Sunkawa H, Kawamura K. Case report: transcatheter arterial embolization for the initial management of intra-abdominal hemorrhage from a hepatic tumor in a cat. Front Vet Sci. 2021;8:707120. doi:10.3389/fvets.2021.707120

    • Search Google Scholar
    • Export Citation
  • 27.

    Weisse C, Nicholson ME, Rollings C, Hammer K, Hurst R, Solomon JA. Use of percutaneous arterial embolization for treatment of intractable epistaxis in three dogs. J Am Vet Med Assoc. 2004;224(8):1307-1311. doi:10.2460/javma.2004.224.1307

    • Search Google Scholar
    • Export Citation
  • 28.

    Ferrozzi F, Tognini G, Bova D, Zuccoli G, Pavone P. Hemangiosarcoma of the adrenal glands: CT findings in two cases. Abdom Imaging. 2001;26(3):336-339. doi:10.1007/s002610000152

    • Search Google Scholar
    • Export Citation
  • 29.

    Ladenheim A, Tian M, Afify A, Campbell M, Kamangar E. Primary angiosarcoma of the adrenal gland: report of 2 cases and review of the literature. Int J Surg Pathol. 2022;30(1):76-85. doi:10.1177/10668969211020099

    • Search Google Scholar
    • Export Citation
  • 30.

    Kobayashi T, Iwai A, Takahashi R, Ide Y, Nishizawa K, Mitsumori K. Spontaneous rupture of adrenal pheochromocytoma: review and analysis of prognostic factors. J Surg Oncol. 2005;90(1):31-35. doi:10.1002/jso.20234

    • Search Google Scholar
    • Export Citation
  • 31.

    Hussain T, Al-Hamali S. Pathophysiology and management aspects of adrenal angiomyolipomas. Ann R Coll Surg Engl. 2012;94(4):224-226. doi:10.1308/003588412X13171221498541

    • Search Google Scholar
    • Export Citation
  • 32.

    Herrera MA, Mehl ML, Kass PH, Pascoe PJ, Feldman EC, Nelson RW. Predictive factors and the effect of phenoxybenzamine on outcome in dogs undergoing adrenalectomy for pheochromocytoma. J Vet Intern Med. 2008;22(6):1333-1339. doi:10.1111/j.1939-1676.2008.0182.x

    • Search Google Scholar
    • Export Citation
  • 33.

    Mayhew PD, Boston SE, Zwingenberger AL, et al. Perioperative morbidity and mortality in dogs with invasive adrenal neoplasms treated by adrenalectomy and cavotomy. Vet Surg. 2019;48(5):742-750. doi:10.1111/vsu.13221

    • Search Google Scholar
    • Export Citation
  • 34.

    Enright D, Dickerson VM, Grimes JA, Townsend S, Thieman Mankin KM. Short- and long-term survival after adrenalectomy in 53 dogs with pheochromocytomas with or without alpha-blocker therapy. Vet Surg. 2022;51(3):438-446. doi:10.1111/vsu.13771

    • Search Google Scholar
    • Export Citation
  • 35.

    Scavelli TD, Peterson ME, Matthiesen DT. Results of surgical treatment for hyperadrenocorticism caused by adrenocortical neoplasia in the dog: 25 cases (1980-1984). J Am Vet Med Assoc. 1986;189(10):1360-1364.

    • Search Google Scholar
    • Export Citation
  • 36.

    Sinclair TJ, Gillis A, Alobuia WM, Wild H, Kebebew E. Surgery for adrenocortical carcinoma: when and how? Best Pract Res Clin Endocrinol Metab. 2020;34(3):101408. doi:10.1016/j.beem.2020.101408

    • Search Google Scholar
    • Export Citation

Contributor Notes

Corresponding author: Dr. Traverson (matraver@ncsu.edu)
  • Figure 1

    Kaplan-Meier survival analysis by tumor type of dogs and cats treated by adrenalectomy for spontaneous adrenal rupture. The survival analysis includes the entire population of dogs and cats diagnosed with either a pheochromocytoma or an adrenocortical tumor (all types confounded) without censoring short-term mortality or cases lost to follow-up. A numerical but statistically nonsignificant difference in median survival time was noted between pheochromocytoma and adrenocortical tumors (P = .583).

  • 1.

    Myers NC III. Adrenal incidentalomas. Diagnostic workup of the incidentally discovered adrenal mass. Vet Clin North Am Small Anim Pract. 1997;27(2):381-399. doi:10.1016/S0195-5616(97)50038-6

    • Search Google Scholar
    • Export Citation
  • 2.

    Anderson CR, Birchard SJ, Powers BE, Belandria GA, Kuntz CA, Withrow SJ. Surgical treatment of adrenocortical tumors: 21 cases (1990-1996). J Am Anim Hosp Assoc. 2001;37(1):93-97. doi:10.5326/15473317-37-1-93

    • Search Google Scholar
    • Export Citation
  • 3.

    Cavalcanti JVJ, Skinner OT, Mayhew PD, Colee JC, Boston SE. Outcome in dogs undergoing adrenalectomy for small adrenal gland tumours without vascular invasion. Vet Comp Oncol. 2020;18(4):599-606. doi:10.1111/vco.12587

    • Search Google Scholar
    • Export Citation
  • 4.

    Daniel G, Mahony OM, Markovich JE, et al. Clinical findings, diagnostics and outcome in 33 cats with adrenal neoplasia (2002-2013). J Feline Med Surg. 2016;18(2):77-84. doi:10.1177/1098612X15572035

    • Search Google Scholar
    • Export Citation
  • 5.

    Mitchell JW, Mayhew PD, Culp WTN, et al. Outcome of laparoscopic adrenalectomy for resection of unilateral noninvasive adrenocortical tumors in 11 cats. Vet Surg. 2017;46(5):714-721. doi:10.1111/vsu.12655

    • Search Google Scholar
    • Export Citation
  • 6.

    Lang JM, Schertel E, Kennedy S, Wilson D, Barnhart M, Danielson B. Elective and emergency surgical management of adrenal gland tumors: 60 cases (1999-2006). J Am Anim Hosp Assoc. 2011;47(6):428-435. doi:10.5326/JAAHA-MS-5669

    • Search Google Scholar
    • Export Citation
  • 7.

    Kyles AE, Feldman EC, De Cock HE, et al. Surgical management of adrenal gland tumors with and without associated tumor thrombi in dogs: 40 cases (1994-2001). J Am Vet Med Assoc. 2003;223(5):654-662. doi:10.2460/javma.2003.223.654

    • Search Google Scholar
    • Export Citation
  • 8.

    Massari F, Nicoli S, Romanelli G, Buracco P, Zini E. Adrenalectomy in dogs with adrenal gland tumors: 52 cases (2002-2008). J Am Vet Med Assoc. 2011;239(2):216-221. doi:10.2460/javma.239.2.216

    • Search Google Scholar
    • Export Citation
  • 9.

    Barrera JS, Bernard F, Ehrhart EJ, Withrow SJ, Monnet E. Evaluation of risk factors for outcome associated with adrenal gland tumors with or without invasion of the caudal vena cava and treated via adrenalectomy in dogs: 86 cases (1993-2009). J Am Vet Med Assoc. 2013;242(12):1715-1721. doi:10.2460/javma.242.12.1715

    • Search Google Scholar
    • Export Citation
  • 10.

    Schwartz P, Kovak JR, Koprowski A, Ludwig LL, Monette S, Bergman PJ. Evaluation of prognostic factors in the surgical treatment of adrenal gland tumors in dogs: 41 cases (1999-2005). J Am Vet Med Assoc. 2008;232(1):77-84. doi:10.2460/javma.232.1.77

    • Search Google Scholar
    • Export Citation
  • 11.

    Barthez PY, Marks SL, Woo J, Feldman EC, Matteucci M. Pheochromocytoma in dogs: 61 cases (1984-1995). J Vet Intern Med. 1997;11(5):272-278. doi:10.1111/j.1939-1676.1997.tb00464.x

    • Search Google Scholar
    • Export Citation
  • 12.

    Gilson SD, Withrow SJ, Orton EC. Surgical treatment of pheochromocytoma: technique, complications, and results in six dogs. Vet Surg. 1994;23(3):195-200. doi:10.1111/j.1532-950X.1994.tb00472.x

    • Search Google Scholar
    • Export Citation
  • 13.

    van Sluijs FJ, Sjollema BE, Voorhout G, van den Ingh TSGAM, Rijnberk A. Results of adrenalectomy in 36 dogs with hyperadrenocorticism caused by adreno-cortical tumour. Vet Q. 1995;17(3):113-116. doi:10.1080/01652176.1995.9694547

    • Search Google Scholar
    • Export Citation
  • 14.

    Knight RC, Lamb CR, Brockman DJ, Lipscomb VJ. Variations in surgical technique for adrenalectomy with caudal vena cava venotomy in 19 dogs. Vet Surg. 2019;48(5):751-759. doi:10.1111/vsu.13168

    • Search Google Scholar
    • Export Citation
  • 15.

    Mayhew PD, Culp WTN, Hunt GB, et al. Comparison of perioperative morbidity and mortality rates in dogs with noninvasive adrenocortical masses undergoing laparoscopic versus open adrenalectomy. J Am Vet Med Assoc. 2014;245(9):1028-1035. doi:10.2460/javma.245.9.1028

    • Search Google Scholar
    • Export Citation
  • 16.

    Cook AK, Spaulding KA, Edwards JF. Clinical findings in dogs with incidental adrenal gland lesions determined by ultrasonography: 151 cases (2007-2010). J Am Vet Med Assoc. 2014;244(10):1181-1185. doi:10.2460/javma.244.10.1181

    • Search Google Scholar
    • Export Citation
  • 17.

    Whittemore JC, Preston CA, Kyles AE, Hardie EM, Feldman EC. Nontraumatic rupture of an adrenal gland tumor causing intra-abdominal or retroperitoneal hemorrhage in four dogs. J Am Vet Med Assoc. 2001;219(3):329-333. doi:10.2460/javma.2001.219.329

    • Search Google Scholar
    • Export Citation
  • 18.

    Williams JE, Hackner SG. Pheochromocytoma presenting as acute retroperitoneal hemorrhage in a dog. J Vet Emerg Crit Care (San Antonio). 2001;11(3):221-227. doi:10.1111/j.1476-4431.2001.tb00087.x

    • Search Google Scholar
    • Export Citation
  • 19.

    Santamarina G, Espino L, Vila M, Lopez M, Alemañ N, Suarez ML. Aortic thromboembolism and retroperitoneal hemorrhage associated with a pheochromocytoma in a dog. J Vet Intern Med. 2003;17(6):917-922. doi:10.1111/j.1939-1676.2003.tb02533.x

    • Search Google Scholar
    • Export Citation
  • 20.

    Kirkwood N, Boland L, Brunel L, Wardman A, Barrs VR. Acute adrenal haemorrhage in two cats with aldosterone-secreting adenocarcinomas. JFMS Open Rep. 2019;5(1):2055116919840828. doi:10.1177/2055116919840828

    • Search Google Scholar
    • Export Citation
  • 21.

    Vandenbergh AG, Voorhout G, van Sluijs FJ, Rijnberk A, van den Ingh TS. Haemorrhage from a canine adrenocortical tumour: a clinical emergency. Vet Rec. 1992;131(23):539-540.

    • Search Google Scholar
    • Export Citation
  • 22.

    Evans K, Hosgood G, Boon GD, Kowalewich N. Hemoperitoneum secondary to traumatic rupture of an adrenal tumor in a dog. J Am Vet Med Assoc. 1991;198(2):278-280.

    • Search Google Scholar
    • Export Citation
  • 23.

    Marti JL, Millet J, Sosa JA, Roman SA, Carling T, Udelsman R. Spontaneous adrenal hemorrhage with associated masses: etiology and management in 6 cases and a review of 133 reported cases. World J Surg. 2012;36(1):75-82. doi:10.1007/s00268-011-1338-6

    • Search Google Scholar
    • Export Citation
  • 24.

    Suyama K, Beppu T, Isiko T, et al. Spontaneous rupture of adrenocortical carcinoma. Am J Surg. 2007;194(1):77-78. doi:10.1016/j.amjsurg.2006.10.028

    • Search Google Scholar
    • Export Citation
  • 25.

    O’Keeffe FN, Carrasco CH, Charnsangavej C, Richli WR, Wallace S. Arterial embolization of adrenal tumors: results in nine cases. AJR Am J Roentgenol. 1988;151(4):819-822. doi:10.2214/ajr.151.4.819

    • Search Google Scholar
    • Export Citation
  • 26.

    Kawamura Y, Itou H, Kida A, Sunkawa H, Kawamura K. Case report: transcatheter arterial embolization for the initial management of intra-abdominal hemorrhage from a hepatic tumor in a cat. Front Vet Sci. 2021;8:707120. doi:10.3389/fvets.2021.707120

    • Search Google Scholar
    • Export Citation
  • 27.

    Weisse C, Nicholson ME, Rollings C, Hammer K, Hurst R, Solomon JA. Use of percutaneous arterial embolization for treatment of intractable epistaxis in three dogs. J Am Vet Med Assoc. 2004;224(8):1307-1311. doi:10.2460/javma.2004.224.1307

    • Search Google Scholar
    • Export Citation
  • 28.

    Ferrozzi F, Tognini G, Bova D, Zuccoli G, Pavone P. Hemangiosarcoma of the adrenal glands: CT findings in two cases. Abdom Imaging. 2001;26(3):336-339. doi:10.1007/s002610000152

    • Search Google Scholar
    • Export Citation
  • 29.

    Ladenheim A, Tian M, Afify A, Campbell M, Kamangar E. Primary angiosarcoma of the adrenal gland: report of 2 cases and review of the literature. Int J Surg Pathol. 2022;30(1):76-85. doi:10.1177/10668969211020099

    • Search Google Scholar
    • Export Citation
  • 30.

    Kobayashi T, Iwai A, Takahashi R, Ide Y, Nishizawa K, Mitsumori K. Spontaneous rupture of adrenal pheochromocytoma: review and analysis of prognostic factors. J Surg Oncol. 2005;90(1):31-35. doi:10.1002/jso.20234

    • Search Google Scholar
    • Export Citation
  • 31.

    Hussain T, Al-Hamali S. Pathophysiology and management aspects of adrenal angiomyolipomas. Ann R Coll Surg Engl. 2012;94(4):224-226. doi:10.1308/003588412X13171221498541

    • Search Google Scholar
    • Export Citation
  • 32.

    Herrera MA, Mehl ML, Kass PH, Pascoe PJ, Feldman EC, Nelson RW. Predictive factors and the effect of phenoxybenzamine on outcome in dogs undergoing adrenalectomy for pheochromocytoma. J Vet Intern Med. 2008;22(6):1333-1339. doi:10.1111/j.1939-1676.2008.0182.x

    • Search Google Scholar
    • Export Citation
  • 33.

    Mayhew PD, Boston SE, Zwingenberger AL, et al. Perioperative morbidity and mortality in dogs with invasive adrenal neoplasms treated by adrenalectomy and cavotomy. Vet Surg. 2019;48(5):742-750. doi:10.1111/vsu.13221

    • Search Google Scholar
    • Export Citation
  • 34.

    Enright D, Dickerson VM, Grimes JA, Townsend S, Thieman Mankin KM. Short- and long-term survival after adrenalectomy in 53 dogs with pheochromocytomas with or without alpha-blocker therapy. Vet Surg. 2022;51(3):438-446. doi:10.1111/vsu.13771

    • Search Google Scholar
    • Export Citation
  • 35.

    Scavelli TD, Peterson ME, Matthiesen DT. Results of surgical treatment for hyperadrenocorticism caused by adrenocortical neoplasia in the dog: 25 cases (1980-1984). J Am Vet Med Assoc. 1986;189(10):1360-1364.

    • Search Google Scholar
    • Export Citation
  • 36.

    Sinclair TJ, Gillis A, Alobuia WM, Wild H, Kebebew E. Surgery for adrenocortical carcinoma: when and how? Best Pract Res Clin Endocrinol Metab. 2020;34(3):101408. doi:10.1016/j.beem.2020.101408

    • Search Google Scholar
    • Export Citation

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