ASSESSMENT IMMUNOHISTOCHEMISTRY OF THE CUTANEOUS PLASMACYTOMA IN A DOG--CASE REPORT/AVALIACAO IMUNOHISTOQUIMICA DE PLASMOCITOMA CUTANEO EM UM CAO: RELATO DE CASO/EVALUACION IMUNOHISTOQUIMICA DE PLASMOCITOMA CUTANEO EN UN PERRO--REPORTE DE UN CASO

Plasmacytomas are uncommon neoplasms in dogs originating in the plasma cells. Occur in any soft tissue, but mainly in the skin, oral cavity and digestive tract. We reported a case of cutaneous anaplastic plasmocytoma in a dog, mixed breed, 16 years old. The animal showed multiple nodules of pinkish color, rough and smooth consistency, spread on the skin. In the histopathological examination revealed circumscribed area consisting of round cells showing intense anisocytosis, anisokaryosis and moderate number of giant cells, multinucleated. The immunohistochemical demonstrated expression for MUM1 and CD79a, allowing diagnosis of anaplastic plasmacytoma.