[A Case of Sigmoid Colon Cancer with Metastasis to the Uterus]

A 65-year-old woman complaining of fetor ex vagina was diagnosed with endometrial adenocarcinoma of the uterus based on the pathological findings of an endometrial biopsy. Sigmoid colon cancer was found on a pre-operative CT scan. Diagnosis of double cancer was made and we performed sigmoidectomy and panhysterectomy with associated resection of both adnexa. Histopathological examination found that the tumor accounted for almost all of the uterine mucosa and over half of the muscular layer. Immunostaining showed CK7 (-), CK20 (+), CDX2 (+), ER (-), and PgR (-), and we diagnosed it as a metastasis to the uterus of the sigmoid colon cancer. The pathological diagnosis was a moderately differentiated adenocarcinoma, pT4b (SI: urinary bladder), pN0 (0/12), H0, P1,M1a (uterus), pStage Ⅳ. As adjuvant chemotherapy, she was administered XELOX for 6 months. Although colorectal cancer rarely metastasizes to the uterus, due to the increase in the prevalence of colorectal cancer, it may be also increase. To choose the best treatment course, it is necessary to diagnose whether it is a primary uterine cancer or a metastatic uterine cancer.