Histiocytosis

Diagnosis

Histiocytosis is a rare disease, thus its diagnosis may be challenging. A variety of tests may be used, including:

• Imaging
  • CT scans of various organs such as lung, heart and kidneys.
  • MRI of the brain, pituitary gland, heart, among other organs.
  • Skeletal survey is useful in children
  • Ultrasound of liver and spleen
• Blood tests: measure cell counts and inflammation
• Breathing tests
• Tissue biopsy and molecular testing to detect mutations

Classification

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:

Alternatively, histiocytoses may be divided into the following groups:

• X-type histiocytoses
• Non-X histiocytoses

Lymphohistiocytosis is a similar immune system disease characterized by the inappropriate activation of natural killer cells, CD8+ cytotoxic T-cells, and macrophages, involving principally the liver, spleen and central nervous system and associated with severe lymphoid atrophy.

Treatments

Various treatments exist for histiocytosis. The one selected depends on the location of the disease and the patient history. The modalities used may include:

• Chemotherapy
  • Cladribine (also known as 2CDA or Leustatin)
  • Etoposide
  • Methotrexate
  • 6-mercaptopurine
  • Vinblastine
• Surgery
• Radiation therapy

Society

Patients and families can gain support and educational materials from the Histiocytosis Association.

The Histiocyte Society, a nonprofit organization, is a group of more than 200 physicians and scientists from around the world committed to improving the lives of patients with histiocytic disorders by conducting clinical and laboratory research into the causes and treatment of this disease. The Society has instituted several clinical trials and treatment plans.

The North American Consortium for Histiocytosis (NACHO) is a group of institutions that collaborate on scientific and clinical research for histiocytic diseases. Established in 2014 by 12 institutions, it was funded through a consortium grant from the St. Baldrick's Foundation.

References

References

1. "Histiocytosis". [[eMedicine]] Dictionary.
2. [http://www.histio.org/page.aspx?pid=378 Disease information] at the Histiocytosis Association
3. "Histiocytosis – Signs and Symptoms". The Regents of the University of California.
4. (January 2018). "Non-neoplastic histiocytic and dendritic cell disorders in lymph nodes". Seminars in Diagnostic Pathology.
5. "Histiocytosis Diagnosis". Memorial Sloan Kettering Cancer Center.
6. (December 1999). "The World Health Organization classification of neoplastic diseases of the hematopoietic and lymphoid tissues. Report of the Clinical Advisory Committee meeting, Airlie House, Virginia, November, 1997". Annals of Oncology.
7. {{EMedicine. ped. 1997. Histiocytosis
8. (2006). "Andrews' Diseases of the Skin: clinical Dermatology". Saunders Elsevier.
9. (May 2022). "StatPearls [Internet]". StatPearls Publishing.
10. (1986). "Lymphohistiocytosis: a multi-factorial syndrome of macrophagic activation clinico-pathological study of 38 cases". Hematological Oncology.
11. "Histiocytosis Treatment". Memorial Sloan Kettering Cancer Center.
12. (16 September 2020). "What is the Histiocyte Society classification of histiocytosis syndromes?".
13. (2007). "Rare Hematological Malignancies". Springer Science & Business Media.
14. "Full Members".