Breast carcinoma, thyroid carcinoma, and T3 thyrotoxicosis in a male cretin.

A male patient with clinical and radiographic evidence of cretinism was found to have T3 thyrotoxicosis. The cause was thought to be a well-differentiated follicular carcinoma of the thyroid. Although the disease was not documented, the patient probably had long-standing hypothyroidism. Untreated primary thyroid failure accompanied by high serum thyroid stimulating hormone (TSH) may be carcinogenic to the thyroid. The association of thyroid abnormalities and male breast carcinoma is discussed.