Rectal gastrointestinal stromal tumor (GIST) in a patient with Crohn's disease: a rare coincidence case report and brief literature review.

Gastrointestinal stromal tumors (GISTs) are the most common type of gastrointestinal mesenchymal tumors. The most common site for developing these neoplasms is the stomach and small intestine. In contrast, anorectal GISTs are very rare. Population-based studies have shown an increased risk of colorectal cancers (CRC) in patients with Crohn's disease (CD). As in sporadic CRC, adenocarcinomas are the most commonly observed tumor. Accordingly, it is expected that rectal mass in CD patients to be an adenocarcinoma. Some reports have presented CD cases with GISTs along the gastrointestinal tract; however, to the best of our knowledge, a rectal GIST has not been reported in CD. Herein, we report a 41-year-old woman with CD who presented with 8 weeks of constipation and was diagnosed with rectal GIST and briefly review existing reports regarding GIST in IBD.