An Unusual Case Report of Duodenojejunal Flexure Tumor With a Systematic Review of the Literature.

The small intestine is the longest segment of the gastrointestinal (GI) tract, but cancers in the small intestine are infrequent. The duodenojejunal (DJ) flexure is an uncommon site for tumors, and those located in these sites are difficult to identify and manage properly. Their rarity, along with ambiguous symptoms that can be readily misattributed to milder conditions, results in a delayed diagnosis when the tumors have significantly advanced. We described the case report of a middle-aged woman presenting with features of intestinal obstruction with gastrointestinal bleeding, showing enteroenteric fistula on enteroscopy and cross-sectional imaging, which was later diagnosed as a case of adenocarcinoma treated with surgical resection. We also systematically reviewed the current literature on DJ flexure tumors and compiled data based on various clinical presentations, radiological findings, associated syndromes, management, and outcomes.