Gastrointestinal Manifestation of Langerhans Cell Histiocytosis

Background: Langerhans cell histiocytosis (LCH) is a rare neoplastic histiocytic disorder with a wide spectrum of presentation that could involve a single system or multiple organ systems. The clinical presentation of LCH is greatly variable. The most commonly involved organs include lungs, bone, skin, pituitary and central nervous system. Gastrointestinal (GI) manifestation, on the other hand, is rarely reported in adults and its natural course remains unknown.

Methods: We conducted a retrospective review of patients presenting with GI involvement at the Mayo Clinic from January 1^st, 2000 to July 20^th, 2022. All patients had a diagnosis of LCH confirmed by histopathologic findings from biopsy, and pathology was reviewed by the department of pathology of Mayo Clinic.

Results: A total of 10 LCH patients with GI involvement were identified. The median age at diagnosis was 51 years (range, 25 - 77 years). Fifty percent of the patients were male. Presenting symptoms include abdominal pain, melena, dysphagia, diarrhea, and hematochezia. Forty percent of patients presented as incidental findings during screening colonoscopy. Sixty percent patients have single system involvement, 30% patients have additional pulmonary involvement, and 10% patients have possible multisystem disease (without definitive biopsy). All patients with pulmonary involvement were smokers at the time of diagnosis. All the patients presented with a single site of GI involvement. The endoscopic findings include erosion/ulceration and polyps. Location of GI involvement includes gastric antrum (20%) and colon (80%). The lesions size ranges from 0.3 cm to 3 cm. Three out of 10 patients have BRAFV600E testing and 100% were positive on immunohistochemistry staining. Mean follow-up time was 49 months. Out of the 6 patients with follow-up data, 4 patients had single system disease and did not have any recurrence after resection; 2 patients had additional pulmonary involvement and diseases remained stable. All the patients were alive at the time of the latest follow-up.

Conclusion: Our study shows that GI manifestation in adult LCH patients involves gastric antrum and colon. In terms of natural history, all patients have single localized lesion in the GI tract and have very low risk of recurrence or dissemination.

No relevant conflicts of interest to declare.