Langerhans cell histiocytosis

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**Langerhans cell histiocytosis**
*Classifications and external resources*
ICD-10	D 76.0
ICD-9	202.5, 277.89
ICD-O:	9752/3
OMIM	604856
DiseasesDB	5906
eMedicine	derm/216

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Langerhans Cell Histiocytosis (LCH) is a very rare disorder that each year is diagnosed in approximately 1 in 200,000 children under the age of 10, and even more rarely, in about 1 in 560,000 adults. While it often can be treated, it unfortunately is often debilitating and even fatal if diagnosed before age 2. Because it is so rare, not much is known about the disease, however, recent research and better communication about the disease has improved its recognition in the medical community.

1 History
2 Symptoms
3 Diagnosis
4 Pathology
5 Treatment
6 See also
7 External links

[edit] History

Because the disease has a variety of different symptoms, depending upon which organs are affected, it used to be known by several different names including:

Histiocytosis-X;
Eosinophilic Granuloma when it affected a single body part;
Hand-Schuller-Christian Syndrome when referring to lesions of the bones and pituitary gland and protuberance of the eyes; and
Letterer-Siwe disease when referring to the severest form of the disease found in infants, involving lesions in the liver, bone marrow, spleen and skin.

[edit] Symptoms

While sometimes there may be generalised signs of illness such as loss of appetite, fever, and anaemia, investigation is usually prompted by one or more of the following symptoms:

a painful lump on a bone
a severe rash resembling cradle cap
chronic ear discharge
swelling due to an enlarged liver or spleen
diabetes insipidus due to a lesion on the pituitary gland
exophthalmos

The symptom underlying all of these signs are histiocytic lesions on skin, bones, lung, liver, spleen, gums, ears, eyes, and/or the central nervous system.

[edit] Diagnosis

Initial diagnosis is made by tissue biopsy. Followup investigation is required to determine the extent of the lesions, and may include X-ray imaging to find lesions in the lungs and bone, blood tests to determine if there is an effect on liver function and red blood cell production and a bone marrow biopsy is also used to determine if there are bone marrow lesions.

[edit] Pathology

An LCH patient produces an excessive number of histiocytes, which cluster around one or more organs of the body, attacking the very same tissues they were assigned to defend from infection. It is not known what causes this abnormal behavior.

[edit] Treatment

Langerhans cell histiocytosis is usually treated much like a cancer using chemotherapy, radiation therapy, and/or surgery. Chemotherapy is by far the most common treatment, with most lesions responding either to chemotherapy or surgery. The most effective drugs used in treatment are Vincristine, Vinblastine, Etoposide and steroids. Radiation therapy on bone lesions is used in rare cases where these do not respond to chemotherapy or surgery. No effective treatment is known when lesions are found in multiple places and include life-supporting organs such as the liver and bone marrow, although chemotherapy will usually be tried.

Some patients need replacement vasopressin, which is administered by nose drops. Where needed, this treatment is usually required for the remainder of the patient's life.

Unlike cancer, LCH can spontaneously go into remission. This is quite likely when only a single body part is affected, so in cases where the disease is localised to one body part and the lesions are not endangering the patient (as in the case where they affect a non-weight bearing bone) no treatment may be offered.

The exact cause of this disease is still unknown, nor is there any known cure.