A clinical, histopathological and flow cytometric study of 149 complete moles, 146 partial moles and 107 non-molar hydropic abortions.

We have compared the clinical and histological features of 149 complete moles with 146 triploid partial moles and 107 diploid non-molar hydropic abortions initially registered as moles for human chorionic gonadotrophin (hCG) follow-up. Forty-one patients with complete moles, five with partial moles and one with hydropic abortion received chemotherapy for hCG elevations interpreted as persistent trophoblastic disease. Complete moles were aborted or were evacuated significantly earlier than partial moles (means of 12.1 and 15.4 weeks; P < 0.001) and hydropic abortions significantly earlier than complete moles (mean 10.7 weeks; P < 0.005). The means of the highest recorded hCG were higher in complete moles (184,056 i.v.) than in partial moles (66,259 i.v.) and hydropic abortion (7942 i.v.). When hCG became normal without chemotherapy, this occurred earlier in patients with hydropic abortion than in those with partial moles (means of 46.7 days and 62.8 days; P < 0.001) and earlier in partial moles than in complete moles (mean 78.3 days; P < 0.005). The incidence of partial moles was comparable throughout fertile years but rose to 1.9 times the average after 40 years. Complete moles were commoner between 14 and 25 years and after 35 years, reaching 4.8 times the average after 40 years. Hydropic abortions were rare before 25 years and increased with age to 12 times the average after 40 years. Stromal karyorrhexis and shape of villi, before they become hydropic, discriminate well between complete and partial mole. Hydrops increased and vascularity decreased with molar age and the presence of non-hydropic villi or vessels did not discriminate between partial mole and the younger complete moles evacuated nowadays.