Use of 2-chlorodeoxyadenosine to treat infantile myofibromatosis.

A 3-year-old boy had fever and bone pain. Magnetic resonance imaging of his femurs showed marrow replacement; iliac crest marrow biopsy revealed myelofibrosis. Although the pathologic criteria for Langerhans cell histiocytosis were not met, the clinical picture led to treatment with etoposide and methylprednisolone, without clinical improvement. One month after presentation, generalized tonic-clonic seizures occurred, and magnetic resonance imaging revealed parenchymal brain lesions. 2-chlorodeoxyadenosine was used. Because of the unexpected lack of response to etoposide and methylprednisolone, a second bone biopsy was performed. The diagnosis was revised to infantile myofibromatosis. After six courses of 2-chlorodeoxyadenosine, brain and bone lesions regressed, with resolution of the clinical symptoms.