Which one of the following not is true regarding choriocarcinoma?

hCG is synthesised by placental syncytiotrophoblast such as in various non-seminomatous germ cell tumours of the testis (e.g. in choriocarcinoma, yolk sac tumour and embryonal carcinoma). However, ectopic hCG production may occur in a variety of non-testicular non-germ cell tumours as well. Ref: TEXTBOOK OF PATHOLOGY 6th EDITION - HARSH MOHAN PAGE NO:709 Choriocarcinoma in females is of 2 types--gestational and nongestational. The marker for both types of choriocarcinoma is hCG. Ref: TEXTBOOK OF PATHOLOGY 6th EDITION - HARSH MOHAN PAGE NO:748