Malignant Lymphoma with Skin Lesions in a Dog

A 12-year-old, castrated male, mongrel dog which had been splenectomized for primary hypersplenism developed enlargement of the submaxillary lymph node and nodular skin lesions 17months after the operation. Histopathological examination of the removed node revealed focal proliferation of atypical lymphocytes. Though the skin lesions once regressed by prednisolone, cyclophosphamide and vincristine treatment in the early stage, the enlargement of the submaxillary lymph nodes and skin lesions recurred and the dog died 213 days after therapy started. By histopathological examination of the necropsy specimen, the present case was diagnosed as epidermotropic, multicentric form of malignant lymphoma.