PLACENTAL SITE TROPHOBLASTIC TUMOR - MOLECULAR ANALYSIS AND CLINICAL-EXPERIENCE

Placental site trophoblastic tumor is a very rare variant of gestation al trophoblastic disease which differs histologically and immunocytoch emically from gestational choriocarcinoma, The English language Litera ture includes only 74 reported cases, Seventeen patients have been man aged at Charing Cross Hospital with this diagnosis, The median follow- up is 4.6 years, and the 5-year overall survival is 80% (95% confidenc e interval, 55-93%). Multivariate regression analysis identified an in terval of > 2 years since the preceding pregnancy as an independent ad verse prognostic factor, Genotypic analysis by PCR allelotyping has co nfirmed the gestational origin of all 11 tumors successfully studied, More detailed molecular analysis has identified the causative pregnanc y for eight tumors. Five were diploid biparental tumors following term pregnancies, and three were androgenetic tumors following monospermic complete hydatidiform moles.