Idiopathic localized dilatation of the ileum in adults: findings on barium studies

Idiopathic localized dilatation of the ileum is a rare entity characterized by a sharply demarcated segmental dilatation of the small bowel that is in line with the lumen. It is probably congenital in origin. Although more commonly diagnosed in children, it presents in adults as occult gastrointestinal (GI) bleeding or less often with abdominal pain. On pathologic examination, the mucosa may be ulcerated, but otherwise the wall is relatively normal. We analyzed the radiographic findings in nine previously unreported cases of this condition in adults.

Collaborative efforts resulted in the collection of nine cases from multiple institutions. In five cases, an enteroclysis had been performed; in three, a conventional small bowel series had been performed; and in one, the lesion was seen on a barium enema with reflux into the ileum. The mean age of patients was 52 years. In seven cases, pathologic correlation was available. In the other two patients, long-term clinical follow-up and repeat studies confirmed the diagnosis. Resected specimens showed a thin but otherwise normal wall with normal ganglion cells and nerve plexuses. Ulceration was noted in six of the seven resected cases. Two cases contained heterotopic gastric mucosa. GI bleeding and/or anemia was the most common (77%) presenting symptom. Abdominal pain and/or obstruction was present in slightly less than half the patients (44%).

Lesions were 6-21 cm long and 4-13 cm wide, and all were located in the ileum. The dilated segments were bilobate in three cases, multilobate in three, spherical in two, and tubular in the other. The dilated area was always in line with the long axis of the bowel, not projecting to the side. No surrounding masses were seen. Except in three patients in whom ulcers were noted, the mucosa was normal.

Idiopathic localized dilatation of the ileum should be suspected whenever a sharply demarcated area of lobulated small bowel dilatation is seen in a middle-aged patient with occult GI bleeding. The axial orientation distinguishes this condition from small bowel diverticula (including Meckel's). The lack of surrounding mass, mucosal irregularity, hypermotility, or fistulae help differentiate it from other causes of small bowel dilatation.