Small bowel adenocarcinoma complicating Crohn's disease: case series and review of the literature.

Colonic adenocarcinoma frequently complicates inflammatory bowel disease of the colon, but small bowel adenocarcinoma (SBA) is a rare complication of Crohn's disease (CD). We present two patients with SBA in CD and review the literature with regards to CD-related SBA. A 45-year-old male with a 17-year history of ileal CD presented with obstructive symptoms but no radiographic evidence of a mass. After laparoscopic ileocolectomy and repair of incidental ileosigmoid fistula, pathology showed a T3N0 adenocarcinoma within the ileal CD. Two years after his resection he was without evidence of disease. A 59-year-old male with a 15-year history of CD presented with an acute exacerbation. Small bowel follow through demonstrated a long ileal stricture for which he underwent an ileocolic resection. Postoperative pathology confirmed a T3N1 CD-related SBA. He died from metastatic cancer 3 months later. Review of the literature identified 154 cases of SBA complicating CD with several distinguishing features from de novo SBA. Patients with SBA and CD are, as a group, younger and more likely to be male. SBA is rarely diagnosed preoperatively in these patients, and has a poor prognosis due to its advanced stage at diagnosis.