[1238] Morphologic Predictors of Early Complete Mole: A Comparison of Histology, p57 and Ploidy

Sucheta A Srivastava, Debra A Bell. Mayo Clinic, Rochester, MN

Background: Complete hydatidiform mole is followed by persistent gestational trophoblastic disease in up to 20% cases and about 50% of choriocarcinomas arise in women with a previous history of complete mole. The risk of such sequelae is <5% following a partial mole which makes it critical to distinguish between the two. With use of effective chemotherapy and highly sensitive b-HCG assays; these patients have a high chance of cure. However with high resolution ultrasound; molar pregnancies are being diagnosed earlier which poses a diagnostic challenge as these do not have the classic histology that is seen in later gestation. Aim of this study was to identify key histological features associated with early complete mole vs other morphologically abnormal gestations.
Design: We retrospectively evaluated 82 first trimester curettage specimens which were previously classified into complete (n=20) and partial or nonmolar hydropic gestation (n=62) based on the results of p57 immunostain and DNA ploidy study by either flow-cytometry or FISH on paraffin embedded tissue. Each specimen was evaluated without prior knowledge of final diagnosis for following features: uniform villous population; short bulbous polypoid terminal villi; trophoblast inclusions; circumferential trophoblastic proliferation; trophoblast atypia; stromal hypercellularity, cisterns, basophilia, karyorrhexis, canalicular network and atypia; absence of fetal nucleated red cells in the villous capillaries and detached sheets of trophoblasts. Results were analysed for sensitivity (SN) and specificity (SP).
Results: SN and SP results for each feature were as follows: uniform villous population (SN, 90%; SP, 70%); short polypoid terminal villi (95%; 32%); trophoblast inclusions (45%; 61%); circumferential trophoblastic proliferation (100%; 11%); trophoblast atypia (100%; 24%); stromal hypercellularity (75%; 55%); cisterns (90%; 42%); stromal basophilia (65%; 73%) stromal karyorrhexis (95%; 82%); stromal atypia (60%; 69%); absence of fetal nucleated red cells (100%; 34%); stromal canalicular network (100%; 26%); detached sheets of trophoblasts (75%; 60%).
Conclusions: Stromal karyorrhexis, uniform villous population, detached sheets of trophoblasts and stromal hypercellularity were strongly associated with complete mole with highest SN and SP. None of the complete moles had nucleated fetal red cells within the villous capillaries. Stromal cisterns, basophilia and atypia demonstrated a good SP. Using a set of these histological criteria will definitely allow an improved diagnostic yield in detecting early complete mole.
Category: Gynecologic & Obstetrics

Tuesday, March 5, 2013 9:30 AM

Poster Session III # 134, Tuesday Morning

 

Close Window