[Preoperative diagnosis of small intestinal cancer associated with Crohn's disease: a case report].

The patient was a 46-year-old woman with a history of Crohn's disease for several years. At 45 years of age, a colonoscopy was performed, and a protruding lesion in the terminal ileum was detected. Pathological analysis of a biopsy specimen noted high suspicion for a well differentiated adenocarcinoma. The patient underwent ileocecal resection, and histological examination of the specimen revealed that infiltration of the well differentiated adenocarcinoma was limited to the mucosa. To the best of our knowledge, this is the first known case of early small intestinal cancer associated with Crohn's disease in Japan. Both endoscopy and a biopsy of any protruding lesions may be useful for making a preoperative diagnosis of small intestinal cancer associated with Crohn's disease.