Hydatidiform mole: two entities

In a continuous series of 811 spontaneous and 1,097 induced abortions, 75 specimens with gross swellings of the chorionic villi were found. On gross morphology, histopatholgy, and karyotype these were classified into two entities: "partial mole" and "complete mole." A total of 56 moles were "partial" (i.e., normal chorionic villi intermingled with hydropic villi) and associated with a fetus, cord, and/or amniotic membrane. The great majority of partial moles (40/49) presented various chromosomal anomalies, especially triploidy and trisomy 16. None of these cases showed marked trophoblastic hyperplasia or anaplasia and, after at least 1 year's follow-up, none had a malignant evolution. A total of 19 moles were "complete," without fetus, cord, or amniotic membrane. Of the 10 cases in which the karyotype could be established, it was 46,XX normal female. The quality of the material of the nine remaining cases did not permit a cytogenetic evaluation; nevertheless, when a search for sex chromatin was possible (seven cases), it was positive. All 19 cases showed marked trophoblastic hyperplasia and anaplasia; two of them presented distant metastases on follow-up. It is considered that "complete" moles constitute a "high-risk group" for malignant trophoblastic neoplasia.