Abstract

BACKGROUND
With the widespread use of high resolution ultrasound in early pergnancy periods, poorly formed diagnostic features of complete hydatidiform mole (CHM) (which mimics normal or nonmolar gestation) often lead to a confusion fo CHM with partial mole, hydropic abortion or nonmolar chromosomal abnormalities.
METHODS
We studied the clinicopathologic finnings in 51 early CHM, evacuated before 12 weeks of gestation to characterize the early histologic changes.
RESULTS
Conventional diagnostic features were not uniformly identified; extensive cavitation was identified in 51.0%, trophoblastic hyperplasia in 49.1%, and avascular villi in 13.7%. The characteristic histologic features of early CHM were cellular and basophilic stroma (82.4%), bulbous projection with linear intervening clefts (76.5%), and apoptotic stromal cells (84.3%). In 86.3%, vascularized chorionic villi showed either primitive vascular network or clearly visible vascular lumen. Nonmetastatic persistent trophoblastic neoplasia developed in 35.3% and all were cured with single-agent or combination chemotherapy. Choriocarcinoma did not develop in any cases. The extent of trophoblastic proliferation at initial curettage han no prognostic value for clinical progression to persistent hydatidiform mole.
CONCLUSIONS
The fact that the histologic features of CHM in early gestation are often not as distinctive as those in later gestation should always be kept in mind in the diagnosis of conceptual products in early gestation.

• Keywords: Hydatidiform Mole-Pregnancy-Chorionic Villi-Blood Vessels;