Abstract
Functioning thyroid metastases are a rare cause of hyperthyroidism. Most of them are follicular carcinoma. Here, we report a case of 62 years old man with a past history of right sub total thyroidectomy for a benign adenoma. Recently, he complained of symptoms of hyperthyroidism associated with left arm pain. Biopsy of the humeral lesion was consistent with a papillary carcinoma of the thyroid metastasis. Postoperatively, he received a cumulative dose of 14.8 GBq of 131-I with a good control of hyperthyroidism but without eradication of the bone metastases.