Intraplacental choriocarcinoma with fetomaternal transfusion

Intraplacental choriocarcinoma is very rare, and is usually found only afte r maternal and fetal metastatic disease is identified. The purpose of this case report is to review the incidence and findings of intraplacental chori ocarcinoma. A term placenta was investigated because the newborn was born w ith severe anemia (Hb 3.0 g/dL). A 2 cm nodule was noted on the surface of the amniotic membrane and grossly resembled an infarction. The tumor was ex amined microscopically with immunohistochemical staining for the alpha- and beta-human chorionic gonadotropin (alpha-hCG, beta-hCG) subunits, human pl acental lactogen (hPL) and Ki-67. Microscopically, the tumor consisted of n ecrotic areas with proliferation of atypical trophoblastic cells and destru ction of the villi and capillaries. The cells were positive for the alpha-h CG, beta-hCG subunits, hPL and Ki-67, consistent with intraplacental chorio carcinoma. The mother and newborn were investigated for the presence of met astatic disease. Computed tomography scans and magnetic resonance imaging o f the mother and infant were negative for metastatic disease. Choriocarcino ma, limited only to the placenta with no evidence of metastatic disease is very rare. Primary intraplacental choriocarcinoma may frequently be over-lo oked or missed, and choriocarcinoma may possibly arise in the placenta more often than in retained or persistent trophoblast following pregnancy.