Microscopically, this lesion is characterized by hyperplasia of cytotrophoblastic and syncytial elements and persistence of villous structures. Choriocarcinoma is a malignant tumor of the trophoblastic epithelium. Uterine muscle and blood vessels are invaded with areas of hemorrhage and necrosis. Columns and sheets of trophoblastic tissue invade normal tissues and spread to distant sites, the most common of which are lungs, brain, liver, pelvis, vagina, spleen, intestines, and kidney. Placental-site trophoblastic disease is an extremely rare tumor arising from the placental implantation site and resembles an exaggerated form of syncytial endometritis.
Trophoblastic cells infiltrate the myometrium, and there is vascular invasion.
Human placental lactogen is present in the tumor cells, while immunoperoxidase staining for HCG is positive in only scattered cells, and serum HCG is relatively low. PDQ statements exist for a number of topics. Please consult the PDQ Index . This document is also available in a text-only format . The information provided through OncoLink should not be used for diagnosing or treating a health problem or a disease.