Coexistent gestational choriocarcinoma and mixed adenocarcinoma of the uterus.

OBJECTIVE

To report the first case of a uterine gestational choriocarcinoma coexisting with an endometrial carcinoma (EC) and to discuss its possible pathogenesis.

MATERIALS AND METHODS

All tissues were examined histologically and monoclonal antibodies were used to evaluate the expression of HCG, HPL, P53, PTEN, and ER. Genotyping was performed on DNA extracted from the freshly dissected choriocarcinoma and the paraffin-embedded endometrial carcinoma along with parental blood DNA using multiplex STR-PCR at 16 loci.

RESULTS

Histology identified two distinct tumors: a uterine tumor containing cytotrophoblastic and syncytiotrophoblastic cells and a second distinct neoplasm composed of adenocarcinoma resembling endometrioid and mucinous adenocarcinoma. Genotyping of the choriocarcinoma revealed alleles from both the patient and her husband and was classified as biparental in origin. The endometrial adenocarcinoma contained only maternal alleles and was thus classified as maternal in origin.

CONCLUSIONS

This is the first description of the simultaneous diagnosis of a uterine gestational choriocarcinoma and an EC within the same patient. DNA genotyping and immunohistochemistry are valuable tools in distinguishing the different origins of coexisting tumors.