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Abstract

CASE DESCRIPTION A 13-year-old Labrador Retriever with a 4-cm-diameter ulcerated perianal mass and a 12-year-old Golden Retriever with a 5-cm-diameter ulcerated caudolateral abdominal mass were brought to a referral oncology practice for evaluation of the dermal masses. Both masses were resected with wide margins without reported postoperative complications. For both dogs, a diagnosis of collision tumor was made. The database of the Veterinary Diagnostic Laboratories at Colorado State University was searched for other examples of collision tumors in dogs.

CLINICAL FINDINGS Histologic assessment of the masses revealed collision tumors in both patients. The perianal mass was diagnosed as a perianal gland carcinoma with adjacent hemangiosarcoma. The flank mass was diagnosed as a fibrosarcoma with an adjacent mast cell tumor. The university database search of sample submissions in 2008 through 2014 for the keywords collision, admixed, or adjacent yielded 37 additional cases of dogs with malignant nontesticular collision tumors.

TREATMENT AND OUTCOME Both dogs were treated with surgery alone and received no adjunctive treatments. Both tumors were completely excised. There was no evidence of either local tumor recurrence or metastasis in the Labrador Retriever and the Golden Retriever at 1,009 and 433 days after surgery, respectively.

CLINICAL RELEVANCE Collision tumors are rare, and there is minimal information regarding treatment recommendations and outcome for animals with collision tumors. On the basis of the 2 cases described in this report, the outcome associated with treatment of collision tumors may be similar to the expected outcome for treatment of any of the individual tumor types in dogs.

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in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine whether results of histologic examination of hepatic biopsy samples could be used as an indicator of survival time in dogs that underwent surgical correction of a congenital portosystemic shunt (PSS).

Design—Retrospective case series.

Animals—64 dogs that underwent exploratory laparotomy for an extrahepatic (n = 39) or intrahepatic (25) congenital PSS.

Procedures—All H&E-stained histologic slides of hepatic biopsy samples obtained at the time of surgery were reviewed by a single individual, and severity of histologic abnormalities (ie, arteriolar hyperplasia, biliary hyperplasia, fibrosis, cell swelling, lipidosis, lymphoplasmacytic cholangiohepatitis, suppurative cholangiohepatitis, lipid granulomas, and dilated sinusoids) was graded. A Cox proportional hazards regression model was used to determine whether each histologic feature was associated with survival time.

Results—Median follow-up time was 35.7 months, and median survival time was 50.6 months. Thirty-eight dogs were alive at the time of final follow-up; 15 had died of causes associated with the PSS, including 4 that died immediately after surgery; 3 had died of unrelated causes; and 8 were lost to follow-up. None of the histologic features examined were significantly associated with survival time.

Conclusions and Clinical Relevance—Findings suggested that results of histologic examination of hepatic biopsy samples obtained at the time of surgery cannot be used to predict long-term outcome in dogs undergoing surgical correction of a PSS.

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in Journal of the American Veterinary Medical Association
in Journal of the American Veterinary Medical Association

Abstract

Case Description—5 Vietnamese potbellied pigs were evaluated for abdominal distress that had not responded to medical treatment (4 pigs) or a draining tract of the cranial abdomen of unknown duration (1 pig).

Clinical Findings—Clinical signs in the pigs included anorexia, vomiting, and constipation. Physical examination revealed a palpable abdominal mass in all pigs. Radiography revealed distended loops of small intestine in 2 pigs.

Treatment and Outcome—3 pigs were treated successfully with wide-margin excision of the abdominal masses, and 2 were euthanized. Primary tumors were diagnosed at necropsy or through histologic evaluation of biopsy specimens obtained during surgery. Types of tumor included cholangiocellular carcinoma, transmural gastric carcinoma, small intestinal adenocarcinoma, metastatic hepatocellular carcinoma, and carcinoma. The tumors involved the stomach, small intestine, spiral colon, liver, and gall bladder. All 3 surgically treated pigs survived at least 9 months after surgery.

Clinical Relevance—Although rare, neoplasia of the alimentary system should be considered among the differential diagnoses for potbellied pigs with signs of abdominal distress. Wide-margin excision of the neoplastic tissue may result in a good outcome in affected pigs.

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in Journal of the American Veterinary Medical Association

Abstract

Objective—To describe the clinical signs, diagnostic findings, surgical management, and outcome in dogs with splenic liposarcoma.

Design—Retrospective case series.

Animals—13 client-owned dogs with splenic liposarcoma.

Procedures—Medical and pathology records of dogs with a histopathologic diagnosis of splenic liposarcoma from 2002 to 2012 were reviewed for the following data: clinical signs, CBC, biochemical profile, thoracic and abdominal imaging, surgical management, histologic grade, and outcome (local recurrence, distant metastasis, and survival time). Telephone interviews were conducted with referring veterinarians.

Results—The median survival time (MST) was 623 days (range, 1 to 1,283 days). In 5 dogs that died of splenic liposarcoma, survival times ranged from 42 to 369 days. Metastasis at the time of surgery was a negative prognostic indicator: the MST was 45 days for dogs with metastasis and 767 days for dogs without metastasis. Dogs with grade 1 splenic liposarcoma had a significantly greater MST (1,009 days), compared with dogs with grade 2 or 3 splenic liposarcoma (MST, 206 and 74 days, respectively).

Conclusions and Clinical Relevance—Results confirmed that splenic liposarcoma is a rare differential diagnosis in dogs with a splenic mass. Survival time was influenced by preoperative clinical stage and histologic grade.

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in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine the efficacy of primary re-excision alone for treatment of soft tissue sarcomas after recent incomplete resection, the frequency and clinical importance of detecting residual tumor in resected scars, and prognostic factors associated with the procedure.

Design—Retrospective case series.

Animals—41 dogs.

Procedures—Medical records of dogs that had undergone recent incomplete excision of a soft tissue sarcoma at a referring veterinary practice and subsequent re-excision of the scar at the Colorado State University Veterinary Medical Center were reviewed.Owners and referring veterinarians were contacted for follow-up information.Slides from re-excised specimens were reviewed.Dogs that underwent radiation therapy after the re-excision procedure were excluded.

Results—41 dogs met the inclusion criteria, and long-term follow-up information was available for 39 dogs.Median follow-up time was 816 days.Local recurrence of tumor developed in 6 of 39 (15%) dogs, and distant metastasis occurred in 4 of 39 (10%) dogs.Healthy tis sue margins of 0.5 to 3.5 cm were achieved at re-excision. Residual tumor was identified in 9 of 41 (22%) resected scars.No tumor-, patient-, or treatment-related variables were associated with local recurrence except for the presence of liposarcoma or fibrosarcoma or whether fine-needle aspiration had been performed prior to surgery.

Conclusions and Clinical Relevance—After incomplete resection of soft tissue sarcomas, resection of local tissue should be performed, even if excisable tissue margins appear narrow.A long-term favorable prognosis is achievable without radiation therapy or amputation. The presence of residual tumor in resected scar tissue should not be used to predict local recurrence.

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in Journal of the American Veterinary Medical Association

Abstract

Objective—To identify matrix metalloproteinases (MMP) 2 and 9 in canine tumor tissue and to compare the amount of activity to that in unaffected stromal tissue.

Animals—30 dogs with spontaneously developing, high-grade osteosarcoma.

Procedure—Tumor and nearby stromal tissue (muscle) were obtained at the time of surgery. Specimens were homogenized, and supernatants were assayed, using gelatin zymography. Human derived standards were run concurrently. Densitometry was done to obtain a semiquantitative arbitrary unit value for each specimen. The amount of activity in tumor tissue was compared with the amount in stromal tissue.

Results—Gelatinolytic bands were observed from the analysis of all tumor tissues and in most stromal tissues. These bands migrated in the same molecular weight area as the human MMP 2 and 9 standards. Gelatinolytic activity could be quenched by the addition of 50 mM EDTA and 1 µg of synthetic tissue inhibitor of metalloproteinase (TIMP) 2 per 100 ml. There was significantly more gelatinolytic activity in tumor tissue than in stromal tissue.

Conclusions and Clinical Relevance—MMP 2 and 9 are detectable in canine neoplastic tissue. matrix metalloproteinases activity in tumor tissue is higher than in unaffected stromal tissue, indicating that canine MMP may be involved in the pathogenesis of tumor growth and metastasis. (Am J Vet Res 2000;61:111–114)

Full access
in American Journal of Veterinary Research

Abstract

In collaboration with the American College of Veterinary Pathologists

Open access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To compare use of doxorubicin, surgery, and radiation versus surgery and radiation alone for treatment of cats with vaccine-associated sarcoma.

Design—Retrospective study.

Animals—25 cats with vaccine-associated sarcomas.

Procedure—Time to first recurrence and survival time were compared between the 2 treatment groups. The number of surgeries (1 or > 1) were compared with respect to time to first recurrence and survival time.

Results—Median time to first recurrence was 661 days for the group that received doxorubicin, surgery, and radiation. Median time to first recurrence has not yet been attained for the group treated with surgery and radiation alone. Median survival time was 674 days for the group treated with doxorubicin, surgery, and radiation and 842 days for the group treated with surgery and radiation alone. For time to first recurrence and survival time, significant differences were not detected between cats that had 1 surgery and those that had > 1 surgery.

Conclusions and Clinical Relevance—Significant differences between the 2 treatment groups were not detected. The efficacy of doxorubicin in the treatment of vaccine-associated sarcomas is uncertain. (J Am Vet Med Assoc 2001;218:547–550)

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in Journal of the American Veterinary Medical Association

Abstract

Objective—To describe outcomes for small-breed dogs with appendicular osteosarcoma.

Design—Multi-institutional retrospective case series.

Animals—51 small-breed dogs.

Procedures—Records from participating Veterinary Society of Surgical Oncology members were searched for dogs that weighed ≤ 15 kg (33 lb) with a histologic diagnosis of appendicular osteosarcoma. The Kaplan-Meier method was used to determine median survival times (MSTs), and Cox regression was performed to identify variables associated with survival time.

Results—Tumors were most commonly located on the humerus (n = 15) and femur (14). Of the 51 study dogs, 9 were treated nonsurgically, 16 underwent amputation of the affected limb only, and 26 underwent curative-intent treatment, with MSTs of 112, 257, and 415 days, respectively. The MST did not differ significantly between dogs in the amputation-only and curative-intent groups. For dogs in the nonsurgical group, MST decreased significantly as the tumor histologic score increased. For dogs in the amputation-only group, MST decreased as body weight increased.

Conclusions and Clinical Relevance—For the small-breed dogs with appendicular osteosarcoma of the present study, tumor histologic grade and mitotic index were subjectively lower and MST following amputation of the affected limb without adjuvant chemotherapy was longer, compared with those for similarly affected larger dogs. Results indicated no significant advantage in MST for dogs that underwent curative-intent treatment versus dogs that underwent amputation only, and further investigation of the importance of adjuvant chemotherapy is warranted.

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in Journal of the American Veterinary Medical Association