Solitary gastric langerhans cell histiocytosis treated by endoscopic submucosal dissection: A case report and literature review

Langerhans cell histiocytosis (LCH) is a rare neoplasm of immature dendritic cells, usually seen in children. Solitary gastric LCH in adults is uncommon, with only a limited number of reported cases. Optimal management remains unclear, although both endoscopic resection and conservative observation have been described in selected localized cases. We report the case of a man in his 50s who presented with several months of postprandial epigastric discomfort partially relieved by proton pump inhibitors. Endoscopy revealed a small, superficially elevated, discolored lesion in the gastric body resembling early gastric cancer. Histopathology and immunohistochemistry showing S-100, CD1a and langerin positivity confirmed LCH. BRAF V600E testing was positive. Systemic evaluation, including PET-CT, bone marrow biopsy, colonoscopy, and laboratory tests, showed no evidence of multisystem disease. After multidisciplinary review, ESD was performed to achieve complete histological assessment and local disease control. The patient remained asymptomatic, with no evidence of residual or recurrent disease during approximately 10 months of follow-up. This case highlights that solitary gastric LCH may closely resemble early gastric cancer on endoscopy, making targeted biopsy, immunohistochemistry, and systemic assessment essential for diagnosis. In selected localized lesions, ESD may serve as a minimally invasive diagnostic and therapeutic option, particularly when complete histological assessment is needed. Longer-term surveillance remains necessary.