Successful treatment of Langerhans cell histiocytosis with 2‐chlorodeoxyadenosine

: Langerhans cell histiocytosis (LCH) is a rare disorder which frequently involves the lungs of affected adults. Recent evidence suggests it is a clonal neoplastic disorder. Prognosis in this disease is variable, but in its multisystem form or when associated with progressive respiratory dysfunction, prognosis is poor. Recent case reports and a phase II trial of the antimonocyte drug 2‐chlorodeoxyadenosine (2CDA) have described success in treating LCH. We used 2CDA to treat a young Australian man with LCH involving lungs and bone. A complete symptomatic remission was achieved with no evidence of recurrence some 5 years after completion of chemotherapy.