Isolated gastric Langerhans cell histiocytosis: a case report and literature review.

Langerhans cell histiocytosis (LCH) is a rare histiocytic disease that predominantly affects young children, with adult cases being exceedingly uncommon. The most frequently affected sites in LCH are bones, lungs, and the pituitary gland, in whom gastrointestinal involvement is scarce. Primary isolated gastric LCH is rarely seen and typically manifests as a polypoid lesion. This article presented a case of LCH in an adult patient, while endoscopic examination revealed an erosive lesion on the greater curvature of the gastric antrum, confirmed by immunohistochemistry. We further discuss the pathogenesis, endoscopic and histopathological characteristics, immunohistochemical findings, relevant differential diagnoses, and current treatment strategies. This report aims to raise clinicians' awareness of the various endoscopic presentations for LCH and emphasizes the importance of thorough histopathological evaluation to obtain an accurate diagnosis and avoid oversight or misdiagnosis.