Published online Jul 28, 2018. doi: 10.3748/wjg.v24.i28.3198
Peer-review started: May 18, 2018
First decision: June 4, 2018
Revised: June 7, 2018
Accepted: June 22, 2018
Article in press: June 22, 2018
Published online: July 28, 2018
The widespread use of capsule endoscopy and balloon-assisted endoscopy has provided easy access for detailed mucosal assessment of the small intestine. However, the diagnosis of rare small bowel diseases, such as cryptogenic multifocal ulcerous stenosing enteritis (CMUSE), remains difficult because clinical and morphological features of these diseases are obscure even for gastroenterologists. In an issue of this journal in 2017, Hwang et al reviewed and summarized clinical and radiographic features of 20 patients with an established diagnosis of CMUSE. Recently, recessive mutations in the PLA2G4A and SLCO2A1 genes have been shown to cause small intestinal diseases. The small bowel ulcers in each disease mimic those in the other and furthermore those found in nonsteroidal anti-inflammatory drug-induced enteropathy. These recent and novel findings suggest that a clinical diagnosis exclusively based on the characteristics of small bowel lesions is possibly imprecise. Genetic analyses seem to be inevitable for the diagnosis of rare small bowel disorders such as CMUSE.
Core tip: The purpose of this letter to the editor is to comment on the differential diagnosis of small intestinal ulcers. Mutations in PLA2G4A and SLCO2A1, encoding proteins involved in the production and degradation of prostaglandins, cause rare gastrointestinal diseases with multiple small intestinal ulcers. In addition to conventional gastrointestinal examinations, genetic analyses are helpful in distinguishing these diseases.