1. Patients with histologicaly diagnosed LCH.
2. Primary registration age is under 20 years old.
3. For LCH-12 registration, sufficient explanation and written consent to the substitute have been obtained. If the patient is 16 years of age or older, he / she must also consent from the person in writing.
4. Prior to acquiring consent to participate in this clinical study, we have obtained consent to submit samples to JPLSG registration and central pathologic diagnosis, and can submit samples within 2 weeks from registration.
1. Patients other than Multiple bone or Multi-system type LCH
2. Patients with organ failure which make difficult to carry out the treatment
3. Patients receiving other treatment except steroids or surgical treatment for LCH
4. Patients with neurodegenerative LCH
5. Patients with any severe bleeding in CNS system
6. Patients with an uncontrolled systemic infection
7. Pregnant women
8. Lactating women
9. Patients whose body weight is less than 2500g
10. Patients with history or concurrent malignancy
11. Patients with a congenital or acquired immunodeficiency syndrome.
12. Informed consent is not obtained from patients and / or the guardians for treatment LCH-12
13. Age is greater than or equal to 20 years old at the start of treatment
14. When the doctor determines that the other inappropriate
Multiple bone type: Induction A (6 weeks) and Early maintenance A (24 weeks)
Multi-system type: Induction A (6 weeks)Patients who had response to Induction A (GR / PR): Early maintenance A (24 weeks) and Late maintenance C (24 weeks)
Multi-system type: Induction A (6 weeks)Patients who had no response to Induction A (NR): Induction B (6 weeks), Early maintenance B (24 weeks) and Late maintenance C (24 weeks)
Event-free survival rates in different type of disease.
Incidence of an adverse event.
Overall survival rates
A response rate of remission induction phase.
The validity of the LCH disease clinical score.
The incidence of irreversible lesions.
Event-free survival rates in all registered cases, including the clinical trials excluded patients.
Overall survival rates in all registered cases, including the clinical trials excluded patients.
Incidence of irreversible lesions in all registered cases, including the clinical trials excluded patients.
Analysis of humoral factors to reflect the disease activity and prognosis of LCH in all registered cases, including the clinical trials excluded patients.