Surgical resection of a mature teratoma on the head of a young cat.

A 4-month-old kitten was presented with a large mass over the temporal area involving the base of the left ear. Cytological evaluation of a fine-needle aspirate was not diagnostic. Computed tomography was used to determine tumor extent. Surgical resection was performed, which included parts of the orbital rim, masticatory muscles, the complete ear canal, and the pinna. Reconstruction of the ocular muscles was performed, and the skin defect was reconstructed using a single pedicle advancement flap. Despite unilateral facial paralysis, postoperative clinical function was excellent and aesthetics were good. Histological examination revealed the tumor to be a teratoma. After a follow-up period of 3 years, no signs of recurrence were evident. Extragonadal teratomas should be considered in the differential diagnosis when young animals are presented with a growing mass located outside the abdominal cavity. Surgical excision of a mature teratoma can be considered curative.