Cutaneous melanoma with metastasis in a cynomolgus monkey (Macaca fascicularis).

ABSTRACT

BACKGROUND: A 3.3-year-old-male cynomolgus macaque (Macaca fascicularis) showed a focally extensive soft, dark, discoid dermal mass, 0.5 cm in diameter, on the dorsal surface of the right hind foot, over the fourth and fifth metatarsal bones. METHODS AND RESULTS Microscopic examination revealed a cutaneous melanoma with local lymphatic invasion, characterized by neoplastic melanocytes within the subcapsular sinus of popliteal and inguinal lymph nodes. The diagnosis was confirmed by immunohistochemistry and transmission electron microscopy. CONCLUSIONS: To our knowledge, this is the first documented case of melanoma in a cynomolgus monkey.