Sebaceous carcinoma in an 8-year old female Boerboel

Summary An uncommon case of metastatic sebaceous carcinoma from an 8-year-old female Boerboel dog was presented to the Truthmiles Veterinary Hospital Lagos, Nigeria. The protruding neoplastic mass was about 6 × 5 × 4 cm with a crater of about 2 cm deep oozing out purulent exudate on the left prescapular region of the left forelimb. After cytological and haematological evaluations, the tumour was processed histopathologically and immunohistochemically. Cytologically, the neoplastic cells appeared individually and in clusters. Cluster cells were round to oval. The nuclei were hyperchromatic, pleomorphic and exhibiting marked anisonucleoliosis. The cytoplasm was moderately basophilic and contained numerous varying sized fine vacuoles. Haematology revealed normocytic normochromic anaemia. Histopathology showed tumour cells characterized by variable degree of sebaceous differentiation, cellular and nuclear pleomorphism, metastases with considerable numbers of mitotic figures. Immunohistochemical evaluation showed strong positive cytoplasmic pan-cytokeratin expression and negative immunoreactivity for S-100 protein. In conclusion, the gross, cytological, histopathological and immunohistochemical features were suggestive of sebaceous carcinoma. To the author's knowledge, this appear to be the first reported case of sebaceous carcinoma in Boerboel breed.