Extragonadal malignant teratoma in a dog - case report

ABSTRACT Teratomas are neoplasms thought to arise from germ cells which usually occur within gonads and are rarely described on extragonadal sites. The present study reports a case of a 15 year old female mongrel dog with a lumbosacral tumor. The tumor was microscopically composed of embryonic tissues with areas containing atypical undifferentiated cells, leading to the diagnosis of a malignant teratoma. Malignant teratomas are uncommon tumors in domestic animals.