Enteroscopic identification of an adenocarcinoma of the small bowel in a patient with previously unrecognized hereditary nonpolyposis colorectal cancer syndrome.

Tumors of the small bowel are uncommon and seldom suspected on a clinical basis. Together with the relative inaccessibility of the small bowel to endoscopic investigation, the rarity of these tumors undoubtedly delays their diagnosis. The case reported is of a patient with an adenocarcinoma of the jejunum presenting as gastrointestinal bleeding of obscure origin. Diagnosis was by push enteroscopy, after several years of unsuccessful radiological and upper and lower endoscopic evaluation. The patient's family fulfilled the Amsterdam criteria for hereditary nonpolyposis colorectal cancer syndrome, which was previously unrecognized. This report emphasizes the value of push enteroscopy and the limits of radiography of the small bowel when investigating patients with obscure GI bleeding. It also underlines the importance of a careful evaluation of the pedigree (concerning history of colorectal and extracolonic cancer) of all patients, including those who present with adenocarcinoma of the small bowel; it is similarly important to consider the possibility of small bowel cancer in members of families with hereditary nonpolyposis colorectal cancer (HNPCC) syndrome.