[Follicular thyroid carcinoma: metastasis to unusual skin locations]

Cutaneous metastasis of thyroid cancer is rare. When it occurs, it usually affects the scalp and neck. We report here a case where follicular thyroid carcinoma metastasized to unusual skin locations.

An 82-year-old woman was followed after a total thyroidectomy for follicular thyroid carcinoma. Assessment after 2 years showed the presence of a small cervical residue, pulmonary metastases, and a high thyroglobulin level. Two sets of internal radiation therapy with iodine 131 (100 mCi each) followed. Response to treatment was poor, and cutaneous and subcutaneous nodules appeared on the abdomen, back, and front left thigh. Biopsy of these lesions showed that they were malignant, and testing with anti-thyroglobulin antibodies confirmed the diagnosis of cutaneous metastasis of follicular thyroid carcinoma.

Although the rare cutaneous metastases of follicular thyroid carcinoma usually occur on the scalp, firm nodular cutaneous lesions that are painless and resist standard treatment in patients with a history of thyroid cancer should suggest the possibility of metastasis.