title: Lack of a y-chromosomal complement in the majority of gestational trophoblastic neoplasms.
abstract: Gestational trophoblastic neoplasms (GTNs) are a rare group of neoplastic diseases composed of choriocarcinomas, placental site trophoblastic tumors (PSTTs) and epithelioid trophoblastic tumors (ETTs). Since these tumors are derivatives of fetal trophoblastic tissue, approximately 50% of GTN cases are expected to originate from a male conceptus and carry a Y-chromosomal complement according to a balanced sex ratio. To investigate this hypothesis, we carried out a comprehensive analysis by genotyping a relatively large sample size of 51 GTN cases using three independent sex chromosome genetic markers; Amelogenin, Protein Kinase and Zinc Finger have X and Y homologues that are distinguishable by their PCR product size. We found that all cases contained the X-chromosomal complement while only five (10%) of 51 tumors harbored the Y-chromosomal complement. Specifically, Y-chromosomal signals were detected in one (5%) of 19 choriocarcinomas, one (7%) of 15 PSTTs and three (18%) of 17 ETTs. The histopathological features of those with a Y-chromosome were similar to those without. Our results demonstrate the presence of a Y-chromosomal complement in GTNs, albeit a low 10% of cases. This shortfall of Y-chromosomal complements in GTNs may reinforce the notion that the majority of GTNs are derived from previous molar gestations.
authors.affiliation: Department of Pathology, Johns Hopkins Medical Institutions, Baltimore, MD 21231, USA.
authors.forename: Kai Lee
authors.initials: KL
authors.lastname: Yap
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Hafez
authors.forename: Tsui-Lien
authors.initials: TL
authors.lastname: Mao
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Kurman
authors.forename: Kathleen M
authors.initials: KM
authors.lastname: Murphy
authors.forename: Ie-Ming
authors.initials: IeM
authors.lastname: Shih