Impact of Risk Organ Involvement on Outcome in Langerhans Cell Histiocytosis (LCH)

Objectives: To compare the outcome in children with low risk vs. risk LCH and to evaluate the impact of individual risk organ on outcome.

Material and Methods: Medical records of 52 patients were reviewed retrospectively (1992 to 2007). Patients were classified into 2 groups: A-low risk (bone, skin and lymph node involvement), B-risk patients (lungs, liver, spleen and bone marrow involvement). Group B further subdivided in B1-isolated lung involvement, B2-liver, bone marrow or both without lung, B3-lung involvement with liver and/or bone marrow. Patients were treated as per histiocytosis society protocols.

Results: There were 31 Males and 21 Females. Mean age at presentation was 4.8 yrs (range 1 month to 15.5 yrs). There were 21 patients in Group A and 31 in Group B with 0 (0%) and 6 (19%) deaths respectively. Overall mortality was 6/52 (11.5%). In group A, 6 patients had skin and lymph node involvement, 6 had unifocal bony involvement and 9 multifocal. Out of these 15 (bony involvement) patients 4 had otitis media and 5 diabetes insipidus. There were 9 patients in Group B1, 18 in Group B2 and 4 in Group B3 with mortality of 0 (0%), 4 (22.2%) and 2 (50%) respectively. Comparison of mortality in risk patients vs. low risk patients approached statistical significance (19.4% vs. 0%, p=0.069). Mortality difference within the 3-subgroups of risk patients was not statistically significant (p=0.097).

Conclusion: Outcome is worse if risk organs are involved. However, isolated lung involvement had trend towards better outcome.