Clear cell carcinoma of the thyroid gland.

Clear cell carcinoma is a rare variant of thyroid cancer, histologically related to the well-differentiated thyroid malignancies. The purpose of this paper is to discuss data collected from the English literature and to present three additional cases. In two of the three cases presented, thyroglobulin levels were extremely high after thyroid ablation. Both cases presented metastasis to lung and bone with significant I131 uptake. It seems that, when compared to the well-differentiated carcinomas of the thyroid gland, clear cell carcinoma has a more aggressive clinical course. Initial radical surgery is the treatment of choice for this kind of neoplasm and I131 should always be considered for the treatment of its metastasis.