Langerhans cell Histiocytosis (LCH) is a rare disease involving clonal proliferation of Langerhans cells, abnormal cells deriving from bone marrow and capable of migrating from skin to lymph nodes. Clinically, its manifestations range from isolated bone lesions to multisystem disease.
LCH is part of a group of clinical syndromes called histiocytoses, which are characterized by an abnormal proliferation of histiocytes (an archaic term for activated dendritic cells and macrophages). These diseases are related to other forms of abnormal proliferation of white blood cells, such as leukemias and lymphomas.
The disease has gone by several names, including Hand-Schüller-Christian disease, Abt-Letterer-Siwe disease, and histiocytosis X, until it was renamed in 1985 by the Histiocyte Society.
Causes, incidence, and risk factors
Histiocytosis X has typically been thought of as a cancer-like condition. More recently researchers have begun to suspect that it is actually an autoimmune phenomenon, in which immune cells mistakenly attack the body, rather than fight infections. Extra immune cells 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.
Histiocytosis X is thought to affect roughly 1 in 200,000 people each year. It is most often seen in children ages 1 to 15. The rate peaks among children ages 5 to10.
Pulmonary histiocytosis X is a specific type of this disorder that involves swelling of the small airways (bronchioles) and small blood vessels in the lungs. It is most common in adults. The inflammation leads to lung stiffening and damage. The cause is unknown. It most often affects those ages 30 to 40, usually cigarette smokers.
Symptoms
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, although there can be some overlap. Tumors in weight-bearing bones, such as the legs or spine, may cause the bones to fracture without apparent reason.
Symptoms in children may include:
- Abdominal pain
- Bone pain (possibly)
- Delayed puberty
- Dizziness
- Ear drainage that continues long-term
- Eyes that appear to stick out (protrude) more and more
- Irritability
- Failure to thrive
- Fever
- Frequent urination
- Headache
- Jaundice
- Limping
- Mental deterioration
- Rash (petechiae or purpura)
- Seborrheic dermatitis of the scalp
- Seizures
- Short stature
- Swollen lymph glands
- Thirst
- Vomiting
- Weight loss
Symptoms in adults may include:
- Bone pain
- Chest pain
- Cough
- Fever
- General discomfort, uneasiness, or ill feeling (malaise)
- Increased amount of urine
- Rash
- Shortness of breath
- Thirst and increased drinking of fluids
- Weight loss
Micrograph showing Langerhans cell histiocytosis. H&E stain.
Signs 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 also include:
- Biopsy of skin to check for the presence of Langerhans cells
- Bone marrow biopsy to check for the presence of Langerhans cells
- Complete blood count (CBC)
- X-rays of all the bones in the body (skeletal survey) to find out how many bones are affected
Histiocytosis X is sometimes associated with cancer. CT scans and biopsy should be done to rule out possible cancer.
Treatment
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 estimated outlook. Such medications may include:
- Cyclophosphamide
- Etoposide
- Methotrexate
- Vinblastine
Other treatments may include:
- Antibiotics to fight infections
- Breathing support (with a breathing machine)
- Hormone replacement therapy
- Physical therapy
- Special shampoos for scalp problems
- Supportive care to relieve symptoms
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