# Isolated gastrointestinal Langerhans cell histiocytosis in a 16‐month‐old child: A case report

## TL;DR

A 16-month-old child with unexplained gastrointestinal symptoms was diagnosed with a rare condition called Langerhans cell histiocytosis and responded well to chemotherapy.

## Contribution

This case report presents an extremely rare instance of isolated gastrointestinal Langerhans cell histiocytosis in a young child.

## Key findings

- A 16-month-old girl with chronic vomiting and bloody diarrhea was diagnosed with GI-LCH.
- The patient showed a favorable response to standard LCH chemotherapy.
- BRAF mutation analysis is suggested as a useful tool for guiding therapy in such cases.

## Abstract

Langerhans cell histiocytosis (LCH) is a rare disorder characterized by clonal proliferation of Langerhans cells, most often involving the skin or bone. Isolated gastrointestinal (GI) involvement is extremely uncommon in young children. We report a 16‐month‐old girl with a 1‐month history of chronic vomiting, bloody diarrhea, and failure to thrive who was found to have GI‐LCH without systemic involvement. She was started on standard LCH chemotherapy with a favorable clinical response. This case highlights the importance of considering LCH in infants/toddlers with unexplained GI symptoms and the utility of targeted molecular testing (e.g., BRAF mutation analysis) in guiding therapy.