Objectives Solitary colorectal metastasis as the first and sole manifestation of spread is a rare occurrence and can be confused with primary intestinal malignancy. We reported our experience in management of sigmoid colon metastasis from medullary breast carcinoma.

Methods We presented here a case rarely reported in literature, showing sigmoid colonic metastasis from breast cancer.

Results A 64-year-old woman with a history of modified radical mastectomy (MRM), followed by adjuvant treatment, performed 19 years ago (2002) for medullar carcinoma in the right breast. She admitted to our hospital for abdominal pain and bowel obstruction syndrome. CT scan showed stenotic eccentric wall thickening of the distal sigmoid colon without metastatic lesion. A colostomy was realized in first time. Followed, secondarily by sigmoidectomy. The subsequent anatomopathological study and immunohistochemistry of the tumor showed metastasis of the carcinoma that was compatible with the primary breast carcinoma. PET-CT was requested and systemic chemotherapy was proposed.

Conclusions There is no consensus on the management of these uncommon lesions. Surgical treatment is reserved for cases of perforation, hemorrhage or intestinal obstruction.