Metastatic thyroid carcinoma of the adrenal gland.

Follicular thyroid carcinoma may spread distant metastases in sites such as bone, lung and brain. In our series of 448 patients with follicular thyroid carcinoma, distant metastases were present in 25% of cases. We report here a case of follicular thyroid carcinoma with a single metastasis at the right adrenal gland, that was found 12 years after total thyroidectomy and radioiodine therapy. Chest X ray, neck and liver echography and total body scan (TBS), performed after radioiodine therapy, were negative. During hormone therapy, serum thyroglobulin (Tg) levels were less than 1 ng/ml until 1990, and then Tg progressively increased in eighteen months up to 149 ng/ml. A new TBS was negative. At computer tomography a node at the right adrenal gland was found. The patient underwent adrenalectomy and histology showed a metastatic follicular thyroid cancer with Hurthle cells. After 1 and 5 months from surgery Tg serum levels were 0.9 ng/ml. This case shows once again the importance of Tg serum levels during follow-up of differentiated thyroid cancer.