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.