Histiocytosis is a general name for a group of disorders or "syndromes" that involve an abnormal increase in the number of immune cells that are called histiocytes.
There are three major classes of histiocytosis:
Langerhans cell histiocytosis, which is also called histiocytosis X
Malignant histiocytosis syndrome (now known as T-cell lymphoma)
Non-Langerhans cell histiocytosis (also known as hemophagocytic syndrome)
This article focuses only on Langerhans cell histiocytosis (histiocytosis X).
Histiocytosis X; Langerhans cell histiocytosis; Eosinophilic granuloma; Pulmonary histiocytosis X; Nonlipid reticuloendotheliosis; Pulmonary Langerhans cell granulomatosis; Hand-Schuller-Christian disease; Letterer-Siwe disease
Histiocytosis X has typically been thought of as a cancer-like condition. But more recently, researchers have begun to think it may be an autoimmune disorder. In this type of disorder, a person's immune cells mistakenly attack the body, rather than help the body fight infections. The extra immune cells the body makes may form tumors, which can affect various parts of the body, including the bones, skull, and other areas.
Some forms of the disorder are genetic, which means they are inherited.
Histiocytosis X is thought to affect roughly 1 in 200,000 people each year. It is most often seen in children ages 1 - 15, with the highest rate among children ages 5 - 10.
Pulmonary histiocytosis X is a specific type of histiocytosis X that involves swelling of the small airways and small blood vessels in the lungs. This inflammation leads to lung stiffening and damage. It is most common in 30 - 40 year old adults, usually cigarette smokers. The cause is unknown.
Histiocytosis X often affects the whole body. A disease that affects the whole body is called a “systemic” disorder.
Symptoms can vary between children and adults, but they may have some of the same symptoms. Tumors in weight-bearing bones, such as the legs or spine, may cause the bones to fracture without an obvious reason.
Symptoms in children may include:
- Abdominal pain
- Bone pain (possibly)
- Delayed puberty
- Ear drainage that continues long-term
- Eyes that appear to stick out more and more
- Failure to thrive
- Frequent urination
- Mental decline
- Seborrheic dermatitis of the scalp
- Short stature
- Swollen lymph glands
- Weight loss
Note: Children over 5 years old often have only bone involvement.
Symptoms in adults may include:
- Bone pain
- Chest pain
- General discomfort, uneasiness, or ill feeling
- Increased amount of urine
- Shortness of breath
- Thirst and increased drinking of fluids
- Weight loss
Exams and Tests
The tumors produce a "punched-out" look on a bone x-ray. Specific tests vary depending on the age of the patient.
Tests in children may include:
- Biopsy of skin to check for Langerhans cells
- Bone marrow biopsy to check for Langerhans cells
- Complete blood count (CBC)
- X-rays of all the bones in the body to find out how many bones are affected
Tests in adults may include:
- Bronchoscopy with biopsy
- Chest x-ray
- Pulmonary function tests
Histiocytosis X is sometimes linked to cancer. CT scans and biopsy should be done to rule out possible cancer.
This disorder is treated with corticosteroids, which suppress immune function (including the dangerous cells). Smoking may worsen the response to treatment and should be stopped.
Children may be given other medications depending on their outlook (prognosis). Such medications may include:
Radiation therapy or surgery may also be used to treat bone lesions.
Other treatments may include:
Antibiotics to fight infections
Breathing support (with a breathing machine)
Hormone replacement therapy
Special shampoos for scalp problems
Supportive care (also called comfort care) to relieve symptoms
Histiocytosis Association -- www.histio.org
Histiocytosis X affects many organs and can lead to death.
About half of those with pulmonary histiocytosis improve, while others have permanent loss of lung function over time.
In very young patients, the outlook depends on the specific histiocytosis and how severe it is. Some children can live a normal life with minimal disease involvement, while others do poorly. Young children, especially infants, are more likely to have body-wide symptoms that lead to death.
Complications may include:
Children may also develop:
- Anemia caused by spreading of the tumors to the bone marrow
- Diabetes insipidus (a rare form of diabetes)
- Lung problems that lead to lung failure
- Problems with the pituitary gland that lead to growth failure
When to Contact a Medical Professional
Call your health care provider if you or your child have symptoms of this disorder. Go to the emergency room if shortness of breath or chest pain develop.
Avoid smoking. Quitting smoking can improve the outcome in people with histiocytosis X that affects the lungs.
There is no known prevention for the childhood forms of this disease.
Ladisch S. Histiocytosis syndromes of childhood. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 19th ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 501.
Raghu G. Interstitial lung disease. In: Goldman L, Ausiello D, eds. Goldman's Cecil Medicine. 24th ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 92.
Jordan BM, Filipovich AH. Histiocytic Disorders. In: Hoffman R, Benz EJ, Silberstein, LE, et al, eds. Hematology: Basic Principles and Practice. 6th ed. Philadelphia, PA: Elsevier Churchill Livingstone; 2012:chap 50.