Melanocitoma dérmico fibroso em bezerra / Fibrous dermic melanocytoma in a heifer

ABSTRACT

Melanomas are neoplasms not frequent in cattle. They constitute less than 2 per cent of all the bovine tumors. This report describes a 11-month-old female Holstein heifer bearing a subcutaneous mass of tissue approximately 18x8cm surrounding the right eye, extending to the top of the neck. This mass appeared when the animal was 4-mounth-old. A biopsy sample taken to histopathology revealed neoplastic tissue composed of melanin-loaded cells and not disorganized connective tissue fibers. Partial pigment removal, utilizing potassium permanganate technique, revealed large nucleus in the melanocitic cells. In some of these cells, a nucleolus was evident. Considering that previous reports on fibrous dermic melanocytoma are rare in the literature, these findings are documented