Malignant Melanoma on the Nasal Planum Treated with Nasal Planectomy in a Cat

Abstract

Non-ocular melanocytic tumor (NOMT) is rare in cats. NOMTs with high proliferative activity on the nose have been suggested to have a poor prognosis, but there is little information on treatment. We performed a nasal planectomy in a cat with a rapidly growing NOMT on the nasal planum. Histologically, the resected tumor was composed of nongranular epithelioid and spindle cells with moderate nuclear atypia and frequent mitotic figures, and it was diagnosed as a malignant melanoma. The tumor cells were near the caudal margin but were determined to be completely resected. No recurrence or metastasis was observed for more than 5 years after surgery. Nasal planectomy may be a therapeutic option for nasal NOMTs without metastasis in cats.