Uterine choriocarcinoma accompanied by an extremely high human chorionic gonadotropin level and thyrotoxicosis.

The conventional treatments given to a 24-year-old woman with metastatic uterine choriocarcinoma and clinical and biochemical thyrotoxicosis did not appear to have any effect, probably due to an extremely high serum human chorionic gonadotropin (hCG) level which was up to 11,910,000 mIU/mL, and were initially underscored in light of the 'high-dose hook effect'. To our knowledge, no extremely high hCG level in a uterine choriocarcinoma patient has been reported in the literature. Her decapacitating symptoms subsided after the first course of chemotherapy by etoposide, methotrexate, and actinomycin D-cyclophosphamide and vincristine (EMA-CO) regimen. The serum hCG level, which reflects the quantification of host tumor burden, returned to the reference range after the fifth course of chemotherapy and the thyroid function reached euthyroid status before the third course of chemotherapy; two final courses were administered after the hCG level became undetectable. Two years after remission of disease, the patient experienced a normal pregnancy, and a term baby girl was delivered vaginally. No recurrence of uterine choriocarcinoma has been noted for 7 years.