Langerhans cell histiocytosis(LCH)is a rare neoplastic disease in dendritic cells.LCH is classified as either a single-system(SS)or multisystem(MS)disease.There is not a standard first-line treatment for LCH in adults.We analyzed the efficacy and safety of immunomodulatory drugs(IMiDs)by searching PubMed/MEDLINE for case reports previously published.The clinical response(nonactive disease or active disease that regressed)was 94%in SS and 53%in MS.IMiDs should only be considered for adults with cutaneous SS involvement;in MS,they should be used only for patients not eligible for more aggressive treatments.