Indolent systemic mastocytosis in a child: A rare and difficult diagnosis

Mastocytosis is a sporadic disease characterized by an abnormal accumulation of mast cells (MCs) in single or multiple organs. A 5-year-old girl who was diagnosed as cutaneous mastocytosis by our Dermatology Department when she was 4 months of age was admitted to our Pediatric Hematology Department by hepatosplenomegaly. Diagnosis of systemic mastocytosis (SM) was verified by one major and one minor WHO criteria: presence of multifocal, dense aggregates of MCs in bone marrow (major criteria) and confirmed by expression of CD2, CD25, and CD117 in bone marrow (minor criteria). During follow-up, systemic anaphylaxis was determined and treated for 3 times. We here present the first report of use of interferon- α -2a, methylprednisolone, and montelukast in life-threatening SM to achieve remission, suggesting a new option for treatment of SM in childhood.