[Follicular carcinoma of the thyroid and diffuse toxic goiter. Case report]

Follicular thyroid cancer rarely manifests itself as a distant metastatic lesion. We report a case of a male with follicular thyroid cancer that presented as a distant metastatic lesion and diffuse toxic goiter.

A 50-year-old man was evaluated because of a soft, painless, pulsating sternal mass of 6 x 6 cm. An incisional biopsy of the soft tissue showed metastatic thyroid follicular neoplasm. History and general examination revealed a weight loss of 10 kg, palpebral retraction and thyrotoxicosis, serum concentration of free thyroxine was elevated and TSH undetectable. A thyroid scan revealed uptake of (131)I in all thyroid areas of 36%. Clinical improvement was observed after methimazole (30 mg/day). Total thyroidectomy was performed: right lobe (5 x 4 x 2 cm), left lobe (4 x 3 x 1 cm), without nodules or lymphadenopathy. During the postoperative period, serum thyroglobulin level was 350 ng/ml, radioiodine treatment (100 mCi) was given, and there was a 75% reduction in the sternal mass. CT of the thorax showed bone destruction in the sternum and soft tissue. Clinical and radiological examination revealed no other metastases. Three months later, thyroid scan was negative and thyroglobulin was 17 ng/ml.

We report this case of follicular thyroid cancer because of its uncommon initial sternal presentation and soft tissue metastasis with diffuse toxic goiter.