Metastatic Cholangiocarcinoma to the Uterus Morphologically Imitating Primary Intestinal-type Endometrioid Adenocarcinoma

Cholangiocarcinoma is an uncommon and aggressive malignancy of intrahepatic and extrahepatic bile ducts. We present a case of a 37-year-old woman with cholangiocarcinoma metastatic to the endometrium that mimicked a primary endometrial adenocarcinoma at resection. The patient is status-post orthotopic liver transplant for cholangiocarcinoma. She presented for evaluation of a clear, odorless vaginal discharge of 6 months' duration. Endometrial biopsy demonstrated an adenocarcinoma with mucinous features similar to primary endometrial adenocarcinoma, but with an immunophenotype consistent with metastatic cholangiocarcinoma. Subsequent hysterectomy demonstrated complete replacement of the native endometrium, a presentation that represents, to our knowledge, the first such reported in the literature. Overall, extragenital metastatic disease to the uterine corpus is rare and involvement of the endometrium even less common. Metastatic cholangiocarcinoma represents a small subset of these metastases to the uterus.