Histiocytic disorders
Langerhans cell histiocytosis
Also called: LCH · Langerhans-cell histiocytosis · histiocytosis X · eosinophilic granuloma · Hand-Schuller-Christian disease · Letterer-Siwe disease · Hand-Schüller-Christian disease · eosinophilic granuloma (historical phenotype names)
What a donor has to do with this
A transplant is not a standard part of treating this condition. It is used rarely, in particular situations, and most people diagnosed with it will not have one.
This is our reading of published transplant guidelines for this condition, not a measurement of how many people need a donor. Where a source actually counted donors, the figure and the people it counted are shown further down. Where none did, we say so rather than estimate.
What the evidence says
- Who it affects
- Childhood populations summarized by NCI LCH PDQ, United States page reviewed 2025, had a median presentation age of 30 months; adult LCH also occurs.
- Treatments other than a transplant
- Risk- and organ-directed chemotherapy (commonly vinblastine plus prednisone), cladribine- or cytarabine-based salvage, and BRAF/MEK-targeted therapy for MAPK-pathway disease; transplant is confined to refractory high-risk multisystem disease.
- If a transplant is used, the cells come from
- Allogeneic bone marrow, peripheral blood stem cells and unrelated cord blood are documented; the dominant source is not reported in the opened disease-specific sources (international paediatric series and reviews, published 2015 and 2025).
- How often the donor was unrelated
- Not reported. No source we could read states this for this condition, so we do not give a number. An estimate here would be a guess dressed as evidence.
Where this gets complicated
Modern MAPK-targeted therapy has changed salvage practice; sources agree HCT is not routine for single-system or pulmonary LCH, but its place relative to prolonged targeted therapy in refractory high-risk multisystem disease remains unsettled.
“HSCT has been used in patients with multisystem high–risk-organ involvement that is refractory to chemotherapy.”
It describes what teams consider in general. It cannot say what applies to any one person. Read the source.
We are not asking you to register on this page
An unrelated donor is not a usual part of treating this condition, so it would be dishonest to use this page to ask you to register. Other conditions in the library are a different story.
Related conditions
Others in histiocytic disorders. They are genuinely different diseases with different treatments — the group name is not a diagnosis.
Where this came from
- WHO Classification of Haematolymphoid Tumours, 5th edition: public classification hierarchy — WHO/IARC, accessed 2026-07-31
- Langerhans Cell Histiocytosis Treatment (PDQ), Health Professional Version — NCI, updated 2025-01-06
- Veys et al., Haematopoietic stem cell transplantation for refractory Langerhans cell histiocytosis: outcome by intensity of conditioning — British Journal of Haematology / PubMed, published 2015-06
- Advances in allogeneic hematopoietic stem cell transplantation for Langerhans cell histiocytosis in children — Frontiers in Pediatrics / PubMed Central, published 2025-02-05