Thyroid Carcinoma in a 13-Year-Old Bengal.

A 13 yr old male neutered Bengal cat was evaluated for a ventral cervical swelling, occasional vomiting, and decreased energy. Serum biochemistry, complete blood count, and physical examination were unremarkable apart from the cervical swelling. Serosanguinous fluid was drained from the cyst-like structure; however, the mass returned. Computed tomographic imaging revealed a large rounded-to-oval-shaped cystic structure in the region of the right thyroid gland with no obvious metastatic changes to the pulmonary parenchyma. The mass was surgically excised, and the tissues were histologically consistent with thyroid carcinoma. No evidence of recurrence or metastasis was present 6 mo postoperatively. Thyroid carcinomas are rarely reported in domestic cats; consequently, there is little research available on the topic. Until more research is made available, veterinarians may look to information available in canine literature to guide their treatment plans, but no definitive statements regarding therapy and ultimate prognosis can be made.