Adenocarcinoma Revealing Ileal Crohn’s Disease

2011

A 39-year-old woman with no relevant medical history presented with occasional episodes of rectal bleeding. The patient denied abdominal pain or any bowel movement disorder. No familial history of colorectal cancer or inflammatory bowel disease was noted. Physical examination was unremarkable, and laboratory findings were normal except a discrete iron deficiency without anemia. An ileocolonoscopy showed normal colorectal mucosa but ulcerations in the distal ileum suggesting Crohn's disease. After transfer into a referral center, an endoscopic videocapsule examination confirmed multiple ileal ulcerations (Figure A) and was then completed by an entero–magnetic resonance imaging showing 2 ileal inflammatory lesions (bowel thickness 10 mm) in the terminal ileum. A lower enteroscopy with chromoendoscopy showed small elevated lesions in the ileum at 15 and 7 cm (Figure B) from the ileocecal valve. Serial and targeted ileal biopsies were consistent with Crohn's disease ileitis, associated with multiple high-grade dysplastic lesions on plane and elevated mucosa. A 20-cm ileocecal resection was performed, and the histologic examination highlighted multiple foci of high-grade dysplasia (Figure C) extendedover the last 15 cm of ileum; some of them behaving as well-differentiated adenocarcinoma infiltrating the submucosa (pT1(sm1)).

Small bowel adenocarcinoma is rare and represents 2% of all digestive cancers. It is well-established that Crohn’s disease is associated with an increased risk of small bowel dysplasia and adenocarcinoma, with a relative risk estimated to be 28.4 compared to the general population.1 The cumulative risk has been described as 0.2% over 10 years and 2.2% over 25 years.2 One hundred seventy-eight cases have been described in the literature. The duration of the disease is undoubtedly the most important risk factor for adenocarcinoma, with a median time of 11 years between diagnosis of Crohn's disease and adenocarcinoma.3 However, in some situations as presented here, findings of adenocarcinoma can be concurrent to the diagnosis of Crohn's disease. It is important to note that all cases of adenocarcinoma occur on ill segments. In fact, the recent development of new therapeutics such as the tumor necrosis factor- blockers and their proven efficacy has led during the past few years to a more exclusively medical approach. This conservative attitude has subsequently led to leave in place inflammatory lesions that are potentially at risk of progression toward dysplasia. As opposed to the colon, the restricted endoscopic accessibility to the small bowel has not allowed enough studies to establish any prevention guideline on dysplasia or early-stage cancer screening. Nevertheless, the growing performance of enteroscopy techniques should enable us to ascertain a systematic small bowel dysplasia screening program in high-risk Crohn's disease patients, namely those with longstanding small bowel inflammatory lesions.

References

  1. Von Roon A, Reese G, Teare J, et al. The risk of cancer in patients with Crohn's disease. Dis Colon Rectum 2007;50:839–855.
  2. Palascak-Juif V, Bouvier AM, Cosnes J, et al. Small bowel adenocarcinoma in patients with Crohn’s disease compared with small bowel adenocarcinoma de novo. Inflamm Bowel Dis 2005;11: 828–832.
  3. Piton G, Cosnes J, Monet E, et al. Risk factors associated with small bowel adenocarcinoma in Crohn’s disease: a case-control study. Am J Gastroenterol 2008;103:1730–1736.