Refractory/relapsed Langerhans cell histiocytosis (LCH) has a difficult course with a guarded prognosis. Salvage treatments available are both expensive and highly toxic. On the basis of the pathophysiology of LCH, we used a novel protocol including pulse dexamethasone and lenalidomide in a child with refractory LCH involving the choroid plexus, which resulted in durable remission with minimal toxicity. The protocol was extrapolated from the FIRST trial for patients with multiple myeloma. We present the clinical course, treatment protocol, and outcome in this child, who is at present disease free and in remission 18 months posttreatment.