Synchronous Colon and Breast Cancers: A Case Report of Multiple Primary Tumors.

Multiple primary malignant tumors (MPMNs) are not rare entities. We report a case of a 50-year-old female who presented with left upper quadrant abdominal pain and GI bleeding. Initial assessment with CT scan revealed a mass originating from the descending colon. Colonoscopy was performed and a fungating partially obstructed mass at the left splenic flexure was detected. Histopathological examination of biopsy was consistent with mucinous adenocarcinoma. The staging CT scan of the chest and pelvis, followed by a mammogram reported a Synchronous breast mass. Core needle biopsy detected an invasive ducal carcinoma. In the multidisciplinary meeting, it was decided to perform the colon procedure first, followed by adjuvant chemotherapy, and then the breast procedure. The patient had an uneventful recovery after both procedures and was sent to the medical oncology department to continue with the treatment.