Identification of choriocarcinoma by the hCG beta-to-hCG proportion in patients with delayed diagnosis caused by contraceptive use.

The use of contraceptives, especially subdermal implants and levonorgestrel-containing intrauterine device (IUD), often cause irregular bleeding. Thus, they may mask unsuspected choriocarcinoma, which also often presents with abnormal bleeding. Choriocarcinoma is mostly curable with combination chemotherapy, but delayed diagnosis can lead to treatment failure. Two cases of choriocarcinoma with considerable delay in diagnosis, due partly to contraceptive use, are reported. The proportion of human chorionic gonadotropin-beta (hCG beta) and total hCG immunoreactivity showed that the proportion of hCG beta was elevated at presentation in both cases.