MAST CELL TUMORS IN CHEETAH (ACINONYX JUBATUS): A CASE SERIES

Mast cell tumors in nondomestic felids are rarely reported and their biological characteristics are not well described. A retrospective review of the pathology records of 52 zoo-housed cheetahs (Acinonyx jubatus) identified five cases of mast cell tumor, involving four closely related individuals. The age at initial presentation varied from 14 mo to 6 yr. Four cases presented as solitary or multiple cutaneous masses that were mostly slow growing, up to 20 mm diameter, and predominantly nonulcerated. The diagnosis was made by fine needle aspiration cytology of a lesion in one case and by excisional biopsy in the others. Histopathologically, the lesions resembled low- to intermediate-grade canine mast cell tumors, with variations in the degree of anisocytosis and anisokaryosis. Surgical excision was incomplete for 80% of the cutaneous lesions, but local recurrence was not observed in any case. One animal with cutaneous lesions subsequently developed fatal visceral mastocytosis involving the spleen, liver, and adrenal gland. There was no evidence of lymph node invasion or paraneoplastic gastrointestinal signs in any of the cases.