Hyperthyroidism in gestational trophoblastic neoplasia.

The thyroid status of twenty-seven African patients with gestational trophoblastic neoplasia (GTN) was studied. Fifteen patients were found to be biochemically hyperthyroid (eight patients with choriocarcinoma; seven with hydatidiform mole). Of these fifteen patients, nine were clinically thyrotoxic. The most serious complication of thyrotoxicosis was life-threatening acute pulmonary oedema with associated cardiac failure. It was found that when serum levels of the human chorionic gonadotrophin (hCG) reached a level of about 0.1 X 10(6) iu/1, thirteen of sixteen patients were biochemically hyperthyroid; at serum levels of 0.3 X 10(6) iu/1 of hCG most patients were clinically thyrotoxic. A feature of hyperthyroidism associated with GTN is that whereas T4 is invariably raised the T3:T4 ratio tends to be low (0.015 +/- 005); rT3:T3 ratios were high in this group. TSH levels were not increased.