Langerhans cell histiocytosis with central nervous system involvement—complete response to 2‐chlorodeoxyadenosine after failure of tyrosine kinase inhibitor therapies with sorafenib and imatinib

Langerhans cell histiocytosis (LCH) is rare in adults, and only a subset of these patients suffers from central nervous system (CNS) involvement. Hence, evidence-based treatment recommendations are lacking. A case of a 20-year-old student with multisystem LCH and extensive CNS involvement is described, who showed a durable response to 2-chlorodeoxyadenosine after prior therapies with the tyrosine kinase inhibitors sorafenib and imatinib. In accordance to the experiences provided by other case series, which are reviewed herein, 2-chlorodeoxyadenosine can be considered an effective and safe option for adult LCH with CNS involvement.