Small bowel obstruction due to metastatic colon cancer

Intraluminal rectal cancer metastasis to the small bowel: An extremely rare case report

Prolonged survival in patients suffering from colorectal cancer (CRC) may lead to the emergence of rare metastatic sites that are not well-documented in the literature. We herein describe a very rare case of an intraluminal small intestinal metastasis in a patient with previously resected CRC. A 71-year-old Caucasian male patient with a history of rectosigmoid junction cancer was initially treated with anterior resection. The tumor was classified as pT3pN0 (0/26) M0, stage II. Eighteen months after the primary surgery, local recurrence was detected in the presacral region, and the patient received combined image-guided radiotherapy and chemotherapy. Two months later, due to residual disease at the level of the anastomosis, the patient underwent additional low anterior resection with a diverting stoma. During extensive adhesiolysis, a small palpable intraluminal mass was identified in the jejunum, and segmental small bowel resection was performed. Pathological examination of the resected specimen confirmed that the lesion was a metastasis from the CRC primary. The precise mechanism and clinical significance of CRC metastasis to the small bowel remain unclear. There is limited clinical experience with this condition, as <20 cases have been reported in the literature to date. The main symptoms leading to evaluation, diagnosis and surgical resection are bowel obstruction and bleeding. The present case highlights the possibility of uncomplicated presence of metastatic CRC in the small bowel. Therefore, dilligent inspection of the peritoneal cavity, including the entire length of the gastrointestinal canal, is of paramount importance, particularly in cases of recurrent CRC.

Late metastatic colon cancer masquerading as primary jejunal carcinoma

Metastasis to the small bowel from a previously resected colorectal cancer is rare and may erroneously be diagnosed as a primary small bowel carcinoma. It usually occurs several years after the primary resection. We present the case of a 67-year-old man who had undergone left hemicolectomy for colon cancer 3 years earlier and returned with subacute small bowel obstruction. This was initially thought, based on preoperative radiological findings and normal colonoscopic examination, to be due a primary jejunal cancer. Even at surgery, the lesion convincingly appeared as an obstructing primary small bowel carcinoma. However, the histology of the resected small bowel revealed metastatic colon cancer. This rare and an unusual metastatic occurrence some years after the primary resection is described and reviewed.