MULTICYSTIC PLACENTAL DISEASE: COMPLETE HYDATIDIFORM MOLE WITH COEXISTING FETUS VS PLACENTAL MESENCHYMAL DYSPLASIA.

We introduce two rare obstetric entities. They show very similar image findings, but the prognosis is different. Prognosis is generally favorable for complete hydatidiform mole with coexisting fetus (CHMCF), but placental mesenchymal dysplasia (PMD) has high fetal and neonatal mortality. Differential diagnosis is essential to management of pregnancy. Twin pregnancies with CHMCF are characterized by the coexistence of complete mole (diploid without fetal parts) and a normal live fetus with a normal placenta. US Findings: 1. Normal fetus and normal placenta with umbilical cord insertion 2. Separated molar placenta, vesicular sonographic pattern Differential Diagnosis: Partial mole (Triploid) Hematoma in placenta (normal β-hCG level) Placental mesenchymal dysplasia Biochemistry: β-hCG concentrations are extremely high • Chorionic villus sampling can be useful to differentiate in early pregnancy between CHMCF and partial hydatidiform mole • Amniocentesis or fetal blood sampling • Genotype of a CHM is entirely of paternal origin • Management of pregnancies with CHMCF has not been standardized • Continuation of CHMCF is an acceptable option: Intensive maternal follow up ultrasonography and β-hCG level monitoring • The chance of a live birth is 7 - 37%. • Complications: Fetal death, vaginal bleeding, preeclampsia, hyperthyroidism, gestational trophoblastic neoplasia Case 1: A 31-year old woman, gravida 2, para 0 CC: IUP at 17 weeks with abnormal placenta. Serum β-hCG levels: 234,358 mIU/mL (elevated) Fetal US: IUP at 17 weeks Twin pregnancy with complete H-mole and coexisting fetus Emergency Cesarian section for fetal distress at 27 wks Delivery: Boy, Apgar score 1'-1, 5'-1 Cytogenetic report: 46, XY, normal Pathological Diagnosis: Complete hydatidiform mole with coexisting fetus Case 2: A 32-year old woman, gravida 1, para 0 CC: IVF pregnancy follow up Serum β-hCG levels: 1,873,485 mIU/mL (elevated) Fetal US: IUP at 8 weeks Twin pregnancy with complete H-mole and coexisting fetus Dilatation and evacuation for vaginal bleeding at 10 weeks Pathological Diagnosis: Complete hydatidiform mole with coexisting fetus Part I: multiple fragments of placental tissue (about 5cc) with variable sized cysts (up to 0.7cm) Part II: multiple fragments of placental tissue (5 × 3cm) without grape like cystic change Developed persistent trophoblastic disease and 18 cycle chemotherapy Case 3: A 34-year old woman, gravida 1, para 0 CC: IVF pregnancy follow up fetus Serum β-hCG levels: 306,645 mIU/mL (elevated) Fetal US: IUP at 17 weeks Twin pregnancy with complete H-mole and coexisting fetus Rare placental lesion estimated to occur in 0.02% of pregnancies. Placental enlargement, dilated and tortuous chorionic vessels, and a focal distribution of cystically enlarged villi. US Findings: Typical large and thickened with multicystic, hypoechoic areas Differential Diagnosis: Partial mole, complete hydatidiform mole with coexisting fetus (CHMCF), chorangioma, intervillous hematoma, infarct or nonspecific hydropic changes • Characteristic morphologic features • Lack of trophoblastic hyperplasia –> maternal serum β-hCG levels are not elevated or only slightly elevated • No known risk of persistent gestational trophoblastic disease • No other specific maternal serum markers • Perinatal demise: not certain, but high as 43% • Cause of fetal death: Massive fetal hemorrhage secondary to rupture of delated periumbilical chorionic vessels Case 4: A 34-year old woman, gravida 1, para 0 CC: IUP at 12 weeks weeks Twin pregnancy with complete H-mole and coexisting fetus Serum β-hCG levels: 39,249 mIU/mL Fetal US: IUP at 12 weeks Twin pregnancy with complete H-mole and coexisting fetus Chorionic Villus Sampling (12 weeks) • Normal appearing placenta: 46, XX Normal • Abnormal appearing placenta: 46, XX Normal QF-PCR: placental mesenchymal dysplasia Pathological Diagnosis: Placental mesenchymal dysplasia Case 5: A 35-year old woman, gravida 2, para 1 CC: IUP 19 weeks, abnormal enlarged and honeycomb shaped placenta Serum β-hCG levels: none Fetal US: IUP at 20 weeks Twin pregnancy with complete H-mole and coexisting fetus R/O Placental mesenchymal dysplasia Amniocenthesis: Mosaicism 47,XY +15[3]/46,XX[31] Pathological Diagnosis: Placental mesenchymal dysplasia Complete Hydatidiform Mole with Coexisting Fetus vs Placental Mesenchymal Dysplasia We proposed two differential diagnosis points 1. Proportion of two patterns of placenta - CHMCF: similar size of two patterns of placenta - PMD: dominant vesicular pattern placenta 2. Umbilical cord insertion - CHMCF: center of normal placenta - PMD: junction of two different patterns of placenta → finally insert into abnormal placenta [ABSTRACT FROM AUTHOR]