Crohn's disease limited to the appendix: a case report in a pediatric patient.

In the original description of Crohn's disease, the appendix was not believed to be involved in the inflammatory process. Later on, case reports started to appear in publications demonstrating that the appendix could be involved in the inflammatory changes of Crohn's disease, and it could also be the primary or the sole manifestation of the disease. Being that appendectomies are one of the most common procedures performed by pediatric surgeons, the knowledge about this diagnosis, all be it rare, is important. Our aim was to report a case and discuss the results of our literature review in order to elucidate the probability of a pediatric patient subsequently developing full Crohn's disease and the follow up that is indicated in such patients. A 12-year-old male patient presented with a history of chronic abdominal pain (3-4 times per week) for 1 year, crampy in nature, localized in the left lower quadrant, and associated with diarrhea (2 episodes per day). There were no extraintestinal manifestations of Crohn's, such as arthralgia or uveitis. Important family history included two paternal uncles with ulcerative colitis both of whom currently have stomas. The only abnormal laboratory value in our patient was an elevated fecal calprotectin level. An esophagogastroduodenoscopy and colonoscopy were performed and found to be unremarkable except for the cecum where it appeared that an exudate was emanating from the appendiceal orifice. A magnetic resonance enterography was ordered and showed an enlarged enhancing appendix. An exploratory laparoscopy identified an appendix with macroscopic cobblestone or lymphoid reaction that histologically was consistent with Crohn's disease. It appears that the Crohn's appendix is more indolent than Crohn's disease of the ileum or colon, with a recurrence rate in the largest series of 8%. The interval time from diagnosis to recurrence varied from 1 to 48 months with an average of 19 months. Some authors debate the need of follow up at all in those patients, believing that the appendectomy alone is curative in the majority of patients. Others recommend follow up for up to 5 years.