Small bowel obstruction secondary to jejunal enterolith

Clinical History

A 59 year old woman presented with symptoms and signs indicative of small bowel obstruction.

Imaging Findings

A 59 year old female with known Crohn’s disease presented with a 3-day history of right iliac fossa pain, nausea and vomiting.
The plain abdominal radiography (Fig 1) showed distension of the small bowel with multiple air-fluid levels in lateral decubitus (not shown), suggestive of small-bowel obstruction. A 6 cm round opacity with calcifications in right iliac fossa was more evident in the radiography after conservative treatment (Fig 2).
An abdominal spiral CT was performed, after intravenous contrast material administration (Fig 3). The images revealed a 6cm sized, round mass in right iliac fossa with laminar concentric calcifications (disposition in onion layers), located in the lumen of an ileal loop. There was no abnormal pattern of bowel wall enhancement or other signs of intestinal ischemia or necrosis. No free peritoneal fluid was found.
The patient underwent laparotomy which confirmed the existence of a large enterolith in the terminal ileum.

Discussion

Enterolith formation is a rare cause of small bowel obstruction. The first radiologic diagnosis of an enterolith was made in 1915 by Pfahler. It has been estimated that approximately one-third of enteroliths are radiopaque and therefore may be identified on abdominal radiographs.
Enterolith formation is thought to be due to bowel hypomotility or stasis. Potential causes for intestinal stasis that promote true enterolith formation include diverticula (Meckel’s or other), afferent loop or stagnant loop syndrome (hypomotility or dysmotility), enteroanastomoses creating a cul-de-sac (blind pouch), and strictures (Crohn’s diasease, tuberculosis).
Because Meckel’s diverticulum is the most frequently encountered diverticulum of the small bowel, it is not surprising that it has been the site of most of the enteroliths reported in the literature.
Enteroliths are an unusual phenomenon in Crohn’s disease that may be associated with longstanding evolution. Crohn’s disease is a chronic, transmural, inflammatory disease of the gastrointestinal tract most frequently affecting the terminal ileum and colon. Longstanding disease may result in cicatricial stenosis of the affected segment. Relative stasis also occurs proximal to intestinal strictures, and enteroliths have been found. The importance of the enterolith in patients with Crohn’s disease is that it indicates underlying stenotic disease.
Clinical signs and symptoms result from the dilatation and progressive stagnation of intestinal contents. Obstruction, mucosal inflammation, oedema, and ulceration leading to perforation can result. The radiologic differential diagnosis of enteroliths is lengthy and includes many extra intestinal entities. The differential diagnosis of enterolith includes appendicolith, fecalith, diverticular stone, bezoar, or a calculus in a Meckel’s diverticulum. Extra intestinal calculi that could mimic an enterolith include calculi from the biliary or genitourinary system (particularly a bladder calculus), calcification of a chylous mesenteric cyst, concretions in a mesenteric lipoma, or a calcified focus of mesenteric fat necrosis. Except for biliary and genitourinary calculi, the entities in the latter list are rare.
Surgical treatment includes removal of enteroliths and correction of stricture by strictureplasty and/or resection.

Differential Diagnosis List

Final Diagnosis

Small bowel obstruction due to an ileal enterolith

URL:	https://eurorad.org/case/7595
DOI:	10.1594/EURORAD/CASE.7595
ISSN:	1563-4086