Sinus histiocytosis with massive lymphadenopathy (Rosai-Dorfman disease) treated with 2-chlorodeoxyadenosine.

Sinus histiocytosis with massive lymphadenopathy (SHML) or Rosai-Dorfman disease (RDD) is a rare but well-defined histiocytic proliferative disorder of unknown etiology that usually presents with cervical lymphadenopathy, fever, leukocytosis, and hypergammaglobulinemia in an otherwise healthy child. Although many patients undergo spontaneous remission, a subset of patients with systemic disease has a more serious course. For those patients with a poor outcome, steroids and chemotherapeutic agents such as etoposide or 6-mercaptopurine plus low dose methotrexate have been used. We present a child with a massive cervical lymphadenopathy treated with 2-chlorodeoxyadenosine (2-CdA, cladribine) after other approaches failed.