title: Thyroid function in gestational trophoblastic neoplasia: evidence that the thyrotropic activity of chorionic gonadotropin mediates the thyrotoxicosis of choriocarcinoma.
abstract: An investigation was made of thyroid function in 20 patients with gestational trophoblastic neoplasia. Two patients were judged to be overtly thyrotoxic on the basis of the symptoms and physical findings; both patients had widely metastatic choriocarcinoma, markedly increased serum T4 levels (21.4 and 27.7 micrograms/100 ml), and extremely high levels of serum human chorionic gonadotropin (hCG) (3,220 and 6,720 IU/ml) relative to those of normal gestation(< 100 IU/ml). Three other patients had moderately increased serum T4 levels (13 to 17.1 micrograms/100 ml), moderately increased serum hCG levels (110 to 310 IU/ml), and findings on clinical examination which suggested euthyroidism. Using the mouse thyroid bioassay, we found that the biologic characteristics of the thyroid-stimulating factor were those of purified hCG, and that the levels of thyroid-stimulating activity in both serum and urine correlated closely with the levels of hCG. These results provide evidence that the thyroid-stimulating activity intrinsic to the hCG molecule plays the central pathophysiologic role in choriocarcinoma-associated thyrotoxicosis.
mesh_terms: D000293:Adolescent; D000328:Adult; D002822:Choriocarcinoma; D006063:Chorionic Gonadotropin / Q000097:blood / Q000502:physiology*; D005260:Female; D006801:Humans; D009362:Neoplasm Metastasis; D011247:Pregnancy; D013961:Thyroid Gland / Q000503:physiopathology*; D013972:Thyrotropin / Q000032:analysis; D014328:Trophoblastic Neoplasms / Q000503:physiopathology*; D014594:Uterine Neoplasms / Q000503:physiopathology*
chemical_list: D006063:Chorionic Gonadotropin; D013972:Thyrotropin