Mucoepidermoid carcinoma of the thyroid gland.

A 20-year-old euthyroid white woman presented with two palpable thyroid nodules. The scintiscan showed an area of increased uptake in the isthmus corresponding with one of the palpable nodules. The uptake in the rest of the gland was diminished including the area of the second palpable nodule which was in the superior portion of the left lobe. Microscopic examination revealed diffuse lymphocytic thyroiditis, follicular adenoma and the isthmus and mucoepidermoid carcinoma of the upper left lobe. No primary site for the muceopidermoid carcinoma outside the thyroid has been identified. Mucoepidermoid carcinoma of the thyroid gland has not previously been reported; the literature is briefly reviewed and etiologic considerations are discussed.