Molar Pregnancies

Molar PregnanciesKoosh Desai

Partial Mole(PM)2 male gametes +1 female gameteXXY(58%), XXX(40%)Some fetal tissue presentSome swollen chorionic villi occurClinically and sonographically: incomplete or missed miscarriage

Imaging of PMClassically snowstorm appearance or bundle of grapes on U/S, but not clear in 1st trimester esp. w/ PM. Heart tone typically not present.

Histopathological Analysis of PMUsually needed for diagnosisNormal appearing villi mixed with swollen, grape-like villi,

GrossMixture of grossly vesicular and normal villi, although not always obvious apparent grossly

Complete Mole(CM)Empty ovum+2 male gametesXX (90%) and XY (10%)No fetus develops, but there is an abnormal placenta consisting of a mass of tissue with grape-like, swollen chorionic villi

Histopathology

Most villi are hypertrophicPresentationExaggerated symptoms of pregnancyVaginal Bleeding: Decidua separates from vaginal wallHyperemesis: extremely high beta-hCG levelsHyperthyroidism: hCG mimics TSHUterine enlargement: from bleedingBenign theca-lutein cysts: from hCG

DiagnosisOften difficult in 1st trimester, especially for PMhCG levels greater than 100,000 mIU/mL (not always)T3/T4 may be elevatedU/S may show bundle of grape appearance or snowstorm patternDefinitive diagnosis requires pathology report

ManagementLook for evidence of metastatic diseaseSuction evacuation, prevents spreadSome studies have shown the incidence of mets lower with prophylactic chemotherapy, especially with high risk CM.(severe symptoms)

Feared complication: ChriocarcinomaHighly malignant tumor that arises from trophoblastic cells within the uterus. Early invasion and Mets.2-4% chance of development in CMhCG should be measured every 2 weeks for at least 6 months post-extraction

CitationsCotran RS, Kumar V, Fausto N, Nelso F, Robbins SL, Abbas AK (2005). Robbins and Cotran pathologic basis of disease (7th ed.). St. Louis, Mo: Elsevier Saunders.Lawler SD, Fisher RA, Dent J (May 1991). "A prospective genetic study of complete and partial hydatidiform moles". Am J Obstet Gynecol. 164 (5 Pt 1): 12707Woo J, Hsu C, Fung L, Ma H (1983). "Partial hydatidiform mole: ultrasonographic features". Aust N Z J Obstet Gynaecol 23 (2): 1037