Langerhans Cell Histiocytosis
A rare buildup of immune cells in the body's tissues
Quick Facts
- Type: Rare blood and immune cell disorder
- Cell involved: Langerhans cells (a type of immune cell)
- Common sites: Bone, skin, lungs, pituitary gland
- Who it affects: Children most often, but any age
Overview
Langerhans cell histiocytosis (LCH) is a rare disorder in which the body makes too many Langerhans cells, a type of white blood cell that normally helps the immune system. In LCH, these cells accumulate abnormally and can form growths that damage tissues and organs.
LCH can affect a single site, such as one bone, or many parts of the body at once, including the bones, skin, lungs, liver, spleen, lymph nodes, and the pituitary gland at the base of the brain. It is most common in children but can occur at any age. The disease behaves more like a clonal disorder of immune cells than a typical infection, and its course ranges from mild and self-limiting to serious and widespread.
Symptoms
Symptoms depend on which organs are involved:
- Bone: Pain, swelling, or a lump, often in the skull, and sometimes a fracture; the most common site.
- Skin: A rash that can look like cradle cap, scaly patches, or small bumps.
- Pituitary gland: Excessive thirst and urination from a condition called diabetes insipidus.
- Lungs: Cough and shortness of breath, especially in adults who smoke.
- General: Fever, fatigue, weight loss, and swollen lymph nodes in widespread disease.
In infants with extensive disease, the liver, spleen, and bone marrow can be affected, which is more serious.
Causes
LCH develops when Langerhans cells acquire genetic changes that cause them to grow and accumulate abnormally. Many cases involve a mutation in a gene that controls cell growth signaling. This has led experts to view LCH as a disorder driven by abnormal immune cells rather than a typical cancer or infection, although it shares features with both.
LCH is not contagious and is not inherited in most cases. In adults, smoking is strongly linked to the lung form of the disease.
Risk Factors
- Childhood, when most cases occur
- Smoking, particularly for lung involvement in adults
- The disorder occurs across all populations and is generally not inherited
Diagnosis
Because symptoms overlap with many other conditions, diagnosis usually requires a biopsy:
- Biopsy: Taking a sample of affected tissue (such as bone or skin) and examining it under a microscope, with special staining to identify Langerhans cells.
- Imaging: X-rays, CT, MRI, or PET scans to find affected bones and organs and assess how widespread the disease is.
- Blood and urine tests: To check organ function and, when the pituitary is involved, to evaluate hormone and fluid balance.
Treatment
Treatment is tailored to how much of the body is involved:
- Single-site disease: May need only observation, a minor procedure, a steroid injection into a bone lesion, or local treatment.
- Multi-site or widespread disease: Often treated with chemotherapy and steroids to control the overactive cells.
- Targeted therapy: Drugs aimed at the specific genetic change may be used in selected cases.
- Supportive care: Hormone replacement for diabetes insipidus and smoking cessation for lung disease.
Many people, especially children with limited disease, do well, though some have lasting effects or disease that returns and needs further treatment.
Prevention
Because the cause is a spontaneous genetic change in immune cells, LCH cannot generally be prevented. However:
- Not smoking lowers the risk of the lung form in adults and helps existing lung disease
- Early evaluation of persistent unexplained bone pain, rashes, or excessive thirst can lead to earlier diagnosis and treatment
When to See a Doctor
See a doctor for persistent unexplained symptoms such as ongoing bone pain or swelling, a rash that does not clear, excessive thirst and urination, or a child with recurring fevers, weight loss, and fatigue. These do not usually mean LCH, but they deserve evaluation. Seek prompt care for breathing difficulty or signs of serious illness.
Frequently Asked Questions
Is Langerhans cell histiocytosis a cancer?
LCH sits between an immune disorder and a cancer. It is driven by genetic changes in immune cells that cause them to grow abnormally, and it is treated by similar specialists, but it is not a typical cancer. Experts often describe it as a clonal disorder of Langerhans cells.
Who gets Langerhans cell histiocytosis?
LCH is most common in children, particularly young children, but it can occur at any age. In adults, the lung form is strongly linked to smoking.
Can LCH be cured?
Many people, especially children with disease limited to a single site, do very well and can be cured or have the disease resolve. Widespread disease is more serious and may need chemotherapy, and some people experience lasting effects or relapses.
What are the most common signs of LCH?
Bone involvement causing pain, swelling, or a lump is the most common feature, especially in the skull. Skin rashes, excessive thirst and urination from pituitary involvement, and, in adults who smoke, lung symptoms are also common.
Is LCH inherited or contagious?
In most cases LCH is neither inherited nor contagious. It results from a genetic change that arises in immune cells during a person's life rather than one passed down in families.
References
- National Cancer Institute (NCI). Langerhans Cell Histiocytosis Treatment.
- Histiocytosis Association. About Langerhans Cell Histiocytosis.
- MedlinePlus, U.S. National Library of Medicine. Histiocytosis.
- Genetic and Rare Diseases Information Center (GARD). Langerhans cell histiocytosis.