Slowly progressive systemic mastocytosis with high mast-cell burden and no evidence of a non-mast-cell hematologic disorder: an example of a smoldering case?

A 43-year-old man with extensive systemic mastocytosis with poor prognostic indicators but no overt hematologic abnormality is described. This patient's clinical presentation and course are consistent with the newly proposed 'smoldering mastocytosis' category. Long-term follow-up of patients is needed to determine whether they may be at higher risk for progression into more aggressive categories.