Hydatidiform Mole, Invasive Mole and Choriocarcinoma in Sweden 1958–1965

. All cases of hydatidiform mole, invasive mole and choriocarcinoma reported to the Swedish Cancer Registry as first diagnosed during the years 1958 through 1965 have been analyzed. The series comprises 631 cases of hydatidiform mole not followed by malignancy, 13 cases of invasive mole, 10 of choriocarcinoma developing after hydatidiform mole and 14 of choriocarcinoma without proven preceding mole. The frequency calculated on the number of medically registered pregnancies (births and abortions) was 1: 1 560 for hydatidiform mole, 1: 77 000 for invasive mole and 1: 41 000 for choriocarcinoma (Table III). The age specific rates per pregnancy rise significantly after the age of 40 both for benign mole and the malignant conditions (Table IV). The 37 cases of invasive mole and choriocarcinoma have been analyzed as to parity, clinical course, metastasis, and survival time (Tables V–IX). It is of considerable prognostic value to separate invasive mole and choriocarcinoma (following the definitions of Hertig and Novak). In this series (histologically revised by the author) all 13 patients with invasive mole (all of them treated with hysterectomy) were living and free from symptoms 2–9 years after the mole delivery. In the group, choriocarcinoma after mole 5 patients are living symptom‐free more than 9 years after the mole delivery, but 5 died from the tumour within 5 years. The group, choriocarcinoma without preceding mole proved most malignant; only 2 out of 14 survived 6–7 years. Of the 9 patients in this group with choriocarcinoma after term or near term pregnancy 8 died within 18 months. The evaluation of chorioepithelial atypia in mole curettages (3 step grading of Hertig) was not shown to be of prognostic value in this study. Regressing lung metastases were shown in 3 out of 13 patients with invasive mole. Five patients dead by metastases of choriocarcinoma were shown to have a normal uterus at autopsy.