Equine nasal and paranasal sinus tumours: Part 2: A contribution of 28 case reports

The clinical and pathological findings of 28 cases (27 horses, 1 donkey) of equid sinonasal tumours examined at the Edinburgh Veterinary School are pr esented and include: seven cases of squamous cell carcinoma (SCC); five ade nocarcinomas; three undifferentiated carcinomas; two adenomas; five fibro-o sseous and bone tumours; and single cases of ameloblastoma, fibroma, fibros arcoma, undifferentiated sarcoma, melanoma and lymphosarcoma. The median ag es of animals affected with epithelial, and fibroosseous/bone tumours were 14 and 4 years, respectively. Unilateral purulent or mucopurulent nasal dis charge (81% of cases) and gross facial swellings (82% of cases) were the mo st common presenting signs with sinonasal tumours, with epistaxis recorded in just 23% of cases. Radiology and endoscopy were the most useful ancillar y diagnostic techniques. The maxillary area was the most common site of tum our origin, and only three cases were definitively identified as originatin g in the nasal cavity. Four of the maxillary SCC lesions originated within the nasal cavities or maxillary sinuses, while two originated in the oral c avity. Fourteen of 15 carcinomas, but only two of the 13 remaining tumours, spread to other sites in the head. Only three cases of sinonasal tumour ha d lymph node metastases, and none had distant metastases. In the long term, surgical treatment with seven malignant tumours was unsuccessful (6 months median survival post-operatively), but was successful with four out Of fiv e benign tumours (no regrowth at a median of 4 years post-operatively).