Linfoma cutâneo não-epiteliotrópico em cão: relato de caso

Abstract

Cutaneous lymphoma is a lymphoid tumor characterized by clonal proliferation of atypical lymphocytes in the skin. Cutaneous lymphomas can be divided into two groups, based on the tropism of neoplastic cells for the epithelium: epitheliotropic cutaneous lymphoma and non-epitheliotropic cutaneous lymphoma, being the first most common form. Non-epitheliotropic lymphoma is more aggressive and may originate from B or T lymphocytes, most of which exhibit rapid progression and infiltration into lymph nodes, with subsequent systemic involvement. The present study aims to report a case of non-epitheliotropic cutaneous lymphoma in an eight-year-old, mixed-breed female canine. After clinical evaluation, the suspicion was of neoplastic lesion and it was made an incisional punch biopsy in the animal. Based on the microscopic changes, the diagnosis of non-epithelitropic cutaneous lymphoma was made and chemotherapy was instituted initially with lomustine, without response, and then with vincristine and cyclophosphamide,also without response. The animal died 41 days after diagnosis and was subjected to necropsy. Samples of skin nodule in the pectoral region, aorta, heart, liver and kidneys were collected and showed similar histological characteristics, with infiltration of round neoplastic cells, the lumen of lymphatic vessels also presented these cells, characterizing metastatic capacity via lymphatics. The prognosis of cutaneous non-epitheliotropic lymphoma is generally reserved and the average survival is one to 36 months, with the survival of a dog with lymphoma that does not respond to treatment is 26 days.