[Association between a meningioma and an occult thyroid carcinoma in congenital hypothyroidism]

The presence of a thyroid carcinoma and a defect in thyroid hormone synthesis in a 27 year ols female is reported. When she was 13 years old a clinical diagnosis of hypothyroid cretinism was made, based on a defect of iodide organification which was demostrated by thiocyanate test showing a discharge of 55 % of 131I at 45 minutes. She intermittently received thyroid hormone until she died. Few days before dying she had normal values of T3, T4 and TSH. Her parents are related and she had a 35 years old sister with a similar type of thyroid hormone synthesis defect. She died with bilateral broncopneumonia following a 3rd grade coma due to a meningioma that compressed the encephalus. The thyroid weighed 12 gms and had a 0.8 x 0.6 x 0.3 cm occult thyroid carcinoma, follicular type, with areas of undifferentiated pattern. As far as we know there are no reports in the literature on the coexistence between an occult thyroid carcinoma and a congetal hypothyroidism without goiter. It may be postulated that the administration of thyroid hormone, inhibiting the release of TSH, may have avoided neoplastic growth despite the low grade of differentation in some areas. The rest of the gland was hypotrophic because of lack of hypophyseal stimulus. This rare coexistence between thyroid carcinoma and meningioma as an autosomal recessive congenital disorder is discussed.