Langerhans cell histiocytosis (LCH) is a rare, cancer-like condition. It occurs when a person’s body makes too many immune cells called histiocytes. The histiocytes attack different tissues of the body. LCH can show up anywhere in the body. It is most common in the skin and bones. It can affect any organ, including the lungs, liver, brain, spleen and lymph nodes.

The disease is more common in children than adults. Symptoms of LCH can vary widely, from mild to severe.