Histiocytosis

Histiocytosis
Classification and external resources
Specialty	hematology
ICD-10	C96.1, D76.0
ICD-9-CM	202.3, 277.89
MedlinePlus	000068
eMedicine	ped/1997
MeSH	D015614
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In medicine, histiocytosis refers to an excessive number of histiocytes, (tissue macrophages), and is typically used to refer to a group of rare diseases which share this as a characteristic. Occasionally and confusingly, the term "histiocytosis" is sometimes used to refer to individual diseases.

According to the Histiocytosis Association of America, 1 in 200,000 children in the United States are born with histiocytosis each year. HAA also states that most of the people diagnosed with histiocytosis are children under the age of 10, although the disease can afflict adults. The University of California, San Francisco, states that the disease usually occurs from birth to age 15.

Histiocytosis (and malignant histiocytosis) are both important in veterinary as well as human pathology.

There are competing systems for classifying histiocytoses. According to the 1999 classification proposed by the World Health Organization, they can be divided into three categories. However, the classifications in ICD10 and MeSH are slightly different, as shown below:

Types of LCH have also been known as "Eosinophilic Granuloma", "Hand-Schuller-Christian Disease", "Letterer-Siwe Disease", and "Histiocytosis X". (See Langerhans cell histiocytosis for details).

Alternatively, histiocytoses may be divided into the following groups:

Patients and families can gain support and educational materials from the Histiocytosis Association, or the Histiocytosis Research Trust. Information concerning histiocytosis and clinicians located in European countries may be found in many languages at the web portal of Euro Histio Net (EHN). This is a project funded by the European Union, co-ordinated by Dr. Jean Donadieu, APHP, Paris, FRANCE. Additional information about Erdheim-Chester Disease can be obtained from the ECD Global Alliance.

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Wikipedia