Distant metastasis to sites other than lymph nodes of borderline ovarian tumor is rare. We describe a case metastasized to sigmoid colon mucosa and submucosa. The metastatic lesion was detected incidentally by screening colonoscopy 7 years after the patient was treated for the primary tumor. The metastatic lesion responded well to treatment with oral Arimidex 1 mg/day. A follow-up colonoscopy with biopsy and imaging studies after 3 months of treatment revealed no evidence of disease in the sigmoid colon. This case showed that the sigmoid colon mucosa and submucosa should be considered as one of distant metastatic sites of a serous borderline ovarian tumor and the favorable response to Arimidex provides support the use of hormone therapy in women with serous borderline ovarian tumor.

Distant metastasis to sites other than lymph nodes of borderline ovarian tumor is rare. We describe a case metastasized to sigmoid colon mucosa and submucosa. The metastatic lesion was detected incidentally by screening colonoscopy 7 years after the patient was treated for the primary tumor. The metastatic lesion responded well to treatment with oral Arimidex 1 mg/day. A follow-up colonoscopy with biopsy and imaging studies after 3 months of treatment revealed no evidence of disease in the sigmoid colon. This case showed that the sigmoid colon mucosa and submucosa should be considered as one of distant metastatic sites of a serous borderline ovarian tumor and the favorable response to Arimidex provides support the use of hormone therapy in women with serous borderline ovarian tumor.