The outcome for feline non-hypersecretory thyroid carcinoma after thyroidectomy

A 14-year-old neutered male cat was presented because of a left ventral cervical mass. Based on imaging, the mass was suspected to have a thyroid origin. There was no evidence of gross metastatic disease or hyperthyroidism. Left thyroidectomy alone was the treatment for this patient and a thyroid carcinoma was diagnosed on histopathology. At last follow-up, 831 days after surgery, there was suspicion of metastasis to the lungs and the cat had developed a right thyroid mass and hyperthyroidism. Key clinical message: This case report identifies a non-hypersecretory thyroid carcinoma. This is a rare diagnosis. The outcome with surgery alone was comparable to that reported for treatment with iodine¹³¹.