A Transplantable Syngeneic Allograft Mouse Model for Nongestational Choriocarcinoma of the Ovary

Nongestational choriocarcinoma is a rare malignancy in humans with poor prognosis. Naturally occurring choriocarcinoma is also rare in laboratory mice, and no genetic mouse model accurately recapitulates the features of this cancer. Here we report development of a genetically engineered mouse (GEM) model with alterations in Brca2, Trp53, and RB that develops ovarian tumors. Most of the ovarian tumors displayed histological characteristics of nongestational choriocarcinoma of the ovary (NGCO) (47%) with abundant syncytiotrophoblasts and cytotrophoblasts, positive immunolabeling for human chorionic gonadotropin, and positive periodic acid-Schiff reaction. The rest of the ovarian tumors were serous epithelial ovarian carcinoma (SEOC) (26%) or mixed tumors consisting of NGCO and SEOC (26%). We further established syngeneic orthotopic mouse models for NGCO by in vivo passaging of GEM tumors. These metastatic models provide a platform for evaluating new treatment strategies in preclinical studies aimed at improving outcomes in choriocarcinoma patients.

Pure nongestational uterine choriocarcinoma in a postmenopausal Chinese woman confirmed with short tandem repeat analysis

Nongestational choriocarcinomas have been observed in the ovaries but rarely the uterus in postmenopausal women. Choriocarcinomas of gestational and nongestational origin have distinct prognoses but cannot be distinguished with routine histologic examination. We report a case of nongestational uterine choriocarcinoma in a 62-year-old Chinese woman that was confirmed with short tandem repeat analysis.