[Epidemiologic and clinicopathologic studies of partial hydatidiform mole]

Area of Science:

• Gynecology
• Obstetrics
• Reproductive Medicine

Background:

• Hydatidiform mole (HM) is a gestational trophoblastic neoplasm.
• Distinguishing between partial hydatidiform mole (PHM) and complete hydatidiform mole (CHM) is crucial for management.
• Previous studies suggest differences in clinical outcomes between PHM and CHM.

Purpose of the Study:

• To compare the epidemiological and clinicopathological characteristics of PHM and CHM.
• To assess the incidence and risk of persistent trophoblastic disease (PTD) in PHM versus CHM.
• To analyze the outcomes of PTD following PHM.

Main Methods:

• A retrospective comparative study of patients diagnosed with molar pregnancies.
• Data collected from the regional registry of Niigata Prefecture and Niigata University Hospital.
• Inclusion of epidemiological data, clinicopathological features, and PTD development.

Main Results:

• From 1971-1988, HM incidence decreased, with PHM rising as CHM declined.
• PTD occurred in 7.9% of CHM cases versus 1.6% of PHM cases in the registry.
• In hospital data (1971-1990), PTD rates were 55.8% for CHM and 17.1% for PHM; PHM-related PTD included invasive mole, metastatic mole, and persistent hCG, but no choriocarcinoma.
• DNA analysis revealed a case of PHM coexisting with CHM and non-molar pregnancy.

Conclusions:

• PHM exhibits a significantly lower incidence of persistent trophoblastic disease (PTD) compared to CHM.
• The epidemiological trends indicate a rise in PHM relative to CHM in recent years.
• While PHM has a lower PTD risk, careful monitoring is essential due to potential complications like invasive mole.