Nuclear DNA content of trophoblastic tumors.

The nuclear DNA content of trophoblasts was measured in 25 cases of normal pregnancy, 46 cases with hydatidiform mole, ten cases with destructive mole and six cases of chorionepithelioma (choriocarcinoma). In normal pregnancy, DNA distribution in syncytiotrophoblasts and cytotrophoblasts showed a sharp peak at the diploid region, although a few cytotrophoblasts with increased DNA content were observed in the first trimester. In chorionepithelioma the DNA content of the trophoblastic cells showed extremely wide distribution without any special peak. In destructive mole, although a wide distribution was observed, the sharp peak was usually noted at the diploid range. Cases with hydatidiform mole were divided into two categories according to the DNA distribution patterns. Type I showed the patterns similar to the first trimester of normal pregnancy and type II resembled the patterns of destructive mole. In hydatidiform mole of type II, subsequent progress towards destructive mole was frequently encountered.