Abstract

A seven year old, male Asian small-clawed otter presented with a 2 x 2 millimeter (mm) red glabrous spot on the left lateral side of the tongue, 3 mm proximal to the tip, in April of 1995. The lesion remained unchanged until April 1996 when it increased to 3 x 8 mm. It was friable upon palpation and bled easily. By May, it involved the distal left one third of the tongue. The entire section of the tongue that was visibly involved was surgically removed. The cut surface was covered with tissue glue. Healing was uneventful. Histopathology revealed a proliferative lesion of the epithelium with invasion of the musculature. There was keratinization in areas and mitotic figures were frequent. The mass was ulcerated and the surrounding tissue was infiltrated with leukocytes, predominantly lymphocytes and plasma cells. The neoplasm extended to the surgical border and was diagnosed as a squamous cell carcinoma. The otter underwent a second surgery one week later to insure all neoplastic tissue was removed. The incision extended from the tip down the midline to one half the length of the tongue, then tapered off to the left. Thus, the left lateral distal half of the tongue was removed. The incision was sutured with 3-0 Vicryl (Ethicon, Inc., Somerville, New Jersey 08876). Healing again was uneventful. The animal ate immediately after recovery from anesthesia. No neoplastic cells were found on histology. Lymph nodes were normal on palpation and no abnormalities were observed on thoracic radiographs. The otter remains asymptomatic at present.