A case of skin metastasis from follicular thyroid carcinoma.

We present a case of skin metastasis from follicular thyroid carcinoma which developed on the scalp of a 72-year-old man. The lesion was noticed 1 month after a surgical excision of the primary thyroid carcinoma and gradually enlarged during the past 11 months. A biopsy from the nodule showed mostly well-differentiated thyroid follicular structures with colloid material. Tumor cells showed mild variation of nuclear size and shape in almost all areas. We performed immunohistochemistry using antithyroglobulin antibody, which established the diagnosis of a metastatic lesion from thyroid follicular carcinoma. Total thyroidectomy and 131I radiotherapy were performed. No further metastasis has been discovered during the last 18 months.