Endometrium-limited metastasis from colon carcinoma

Extragenital tumors uncommonly affect the female genital tract and usually involve the ovaries (75-80%), while the uterus can harbor metastases in the context of a widely disseminated disease. The primary tumors are most often located in the breast (35%) or gastrointestinal tract (38%). Metastases to the uterine body usually involve the myometrium whereas those exclusively involving the endometrium are rare. We report the case of a 50-year-old woman with endometrial metastasis from a colonic adenocarcinoma 6 years after the initial presentation. Metastatic colon tumors can histologically present as a primary disease in the endometrium if the pathologist has little awareness to consider metastasis. The clinical history of disseminated metastases, the lack of CK7 expression at immunohistochemistry, and positive results for CK20 and nuclear CDX2 are helpful clues to support the diagnosis of metastatic carcinoma of colorectal origin.