Mammary gland chondrosarcoma in a German Shepherd bitch: A case report.
Canine mammary tumours are the most common tumours in intact bitches and they constitute about 25% of the neoplasm in this species followed by skin tumours (Benjamin et al.,1999) and their incidence varies from 198 to 622.6 cases per 100,000 dogs per year (Vail and MacEwen,2000). According to Yager et al.(1993),about 95% of them are of epithelial origin while the other 5% are mesenchymal. Sorenmo (2003) reported that half of the surgically removed mammary neoplasms in bitches were malignant. Mammary neoplasms in dogs that are similar to those in humans are of special concern to oncology researchers because they may be used as biological models in the search for more accurate diagnosis, more exact prognosis and a more efficient therapeutic procedures (Pierrepoint, 1985). Reports of this condition in indigenous Nigerian dogs have not been documented. In this report, we present the clinical and histopathological findings associated with mammary chondrosarcoma in a 13-year old German Shepherd bitch. Based on our review of literature, extra skeletal chondrosarcoma is extremely rare when compared with other types of canine mammary tumours (Menten,2002) The tumor, measured 8cm in diameter, was located in the right caudoabdominal mammary gland and the mass weighed 350g. It was very hard with many irregular nodular projections on the surface. Microscopically, a well differentiated chondrosarcoma of the mammary gland was diagnosed. The diagnosis of canine mammary chondrosarcoma is an uncommon occurrence in this environment.
KEYWORDS: Dog, mammary gland, chondrosarcoma