History
A 3-year-old Boer goat doe was evaluated at the University of Georgia Large Animal Teaching Hospital because of chronic, progressive inspiratory dyspnea and bilateral nasal discharge. The goat had developed a thick, seromucoid bilateral nasal discharge and an increased respiratory effort approximately 4.5 months prior to evaluation. Discharge was more severe from the left nasal passage. The goat had been treated with several courses of penicillin G procaine, dexamethasone, and flunixin meglumine (doses not reported) with minimal improvement. Other goats in the herd were all reportedly healthy.
On physical examination, the goat was quiet but alert, responsive, and in excellent body condition with a body condition score of 3 of 5. Respiratory effort was increased at rest, air flow from the left nasal passage was reduced, and open-mouth breathing occurred following handling. Palpation of the skull revealed a firm, raised swelling rostroventral to the medial canthus of the left eye. No abnormalities were appreciated on palpation of the peripheral lymph nodes. Cardiothoracic auscultation revealed increased bronchovesicular sounds and an inspiratory wheeze referred from the upper airways. Rumen contractions were inaudible in the left paralumbar fossa. The remainder of findings on the physical examination were within reference limits. A CBC and plasma biochemistry analysis were performed and revealed polycythemia (Hct, 38%; reference range, 22% to 36%) and hyperproteinemia (8.1 g/dL; reference range, 6.0 to 7.5 g/dL) characterized by hyperglobulinemia (4.8 g/dL; reference range, 2.7 to 4.4 g/dL). Skull radiography was performed (Figure 1).
Right lateral (A) and dorsoventral (B) radiographic views of the skull of a 3-year-old Boer goat doe with chronic, unilateral, mucoid nasal discharge. R … Right.
Citation: Journal of the American Veterinary Medical Association 242, 9; 10.2460/javma.242.9.1219
Determine whether additional imaging studies are required, or make your diagnosis from Figure 1—then turn the page →
Radiographic Findings and Interpretation
On the lateral projection, 3 well-defined, ovoid soft tissue opaque structures are present within the left maxillary sinus (Figure 2). From rostral to caudal, the masses measure 4, 2.2, and 2.6 cm in diameter. On the dorsoventral projection, the masses completely occupy the left maxillary sinus. Expansion of the sinus and possible extension of the mass into the nasal passage has caused deviation of the nasal septum to the right. On the basis of radiographic findings, differential diagnoses included abscess, tumor, granuloma, and formation of a cystic structure.
Same radiographic images as in Figure 1. Note the 3 well-defined, rounded opacities within the left maxillary sinus (arrows; A and B), which cause deviation of the nasal septum to the right. R … Right.
Citation: Journal of the American Veterinary Medical Association 242, 9; 10.2460/javma.242.9.1219
Treatment and Outcome
Upper airway endoscopy revealed a firm, round, pink mass almost entirely obstructing the lumen of the left nasal passage such that passage of the endoscope into the nasopharynx was impossible. The mucosa covering the mass appeared healthy. The caudal extent of the right nasal passage appeared narrowed subsequent to deviation of the nasal septum, and protrusion of a mass beyond the nasal septum into the nasopharynx was evident.
Surgical extirpation of the masses was offered but was declined because of financial constraints. Owing to the progressive nature of the condition, lack of response to previous treatments, and poor prognosis for resolution without surgery, euthanasia was elected and a necropsy performed. Gross examination at necropsy revealed a 5 × 5-cm bony, irregularly shaped cystic cavity continuous with the maxillary sinus that contained a large volume of thick, yellow, seromucoid fluid. On histologic examination, the cyst was lined with pseudostratified, ciliated, columnar respiratory-type epithelium. Final histopathologic diagnosis was a sinonasal cyst.
Comments
Sinonasal or maxillary cysts are uncommon in horses but rank only behind sinusitis as a cause of sinonasal disease in some equine studies.1,2 Sinonasal cysts have been only rarely reported for other species. Clinical signs in horses and other species can be present for a variable time and include a nonmalodorous nasal discharge, facial distortion, abnormal respiratory noise, and progressive respiratory difficulty.1 Skull radiography and upper airway endoscopy are the initial diagnostic modalities of choice. Radiographic findings suggestive of sinonasal cysts include rounded structures in the maxillary sinus with a homogenous soft tissue opacity. Partial mineralization of the capsule and deviation of the septum can also be present.2 In the goat of the present report, radiographic findings were suggestive of a nonneoplastic or benign neoplastic process. Malignant neoplastic or infectious processes are more likely to have ill-defined margins, more extensive osteolysis, and draining tracts.
Definitive diagnosis of a sinonasal cyst requires biopsy and histologic analysis of the cyst wall. Histopathologic changes in the goat of the present report were similar to those reported for horses and included edema, fibrosis, and lymphoplasmacytic inflammation, perhaps indicating a chronic inflammatory process.3 However, the exact origin of sinonasal cysts remains speculative. Sinonasal cysts in horses share similarities with human mucocoeles.3 An association with ethmoid hematomas has been proposed in horses; however, this was not supported by histologic findings in 1 study.3 In horses, the prognosis for sinonasal cysts is generally good, with > 80% of affected patients having complete remission of clinical signs following surgical intervention.4
1. Woodford NS, Lane JG. Long term retrospective study of 52 horses with sinonasal cysts. Equine Vet J 2006; 38: 198–202.
2. Tremaine WH, Dixon PM. A long-term study of 277 cases of equine sinonasal disease. Part 1: details of horses, historical, clinical and ancillary diagnostic findings. Equine Vet J 2001; 33: 274–282.
3. Tremaine WH, Clarke CJ, Dixon PM. Histopathological findings in equine sinonasal disorders. Equine Vet J 1999; 31: 296–303.
4. Tremaine WH, Dixon PM. A long-term study of 277 cases of equine sinonasal disease. Part 2: treatments and results of treatments. Equine Vet J 2001; 33: 283–289.
