Mastocytosis: a disease of the hematopoietic stem cell.

INTRODUCTION: Mastocytosis is an unusual clonal disease of the hematopoietic stem cell.

METHODS: This article is based on a selective literature search and on the authors' clinical and pathological experience.

RESULTS: The clinical manifestations of mastocytosis range from cutaneous mastocytosis, a common, prognostically favorable presentation, to mast cell leukemia, a rare, life-threatening disease. The mediator-induced symptoms usually respond well to H1 antihistamines. Therapeutic standards for cytoreduction in the progressive, systemic forms of mastocytosis are still lacking.

DISCUSSION: Because some of the manifestations of mastocytosis are nonspecific and can be mimicked by other diseases, there is a risk of two types of diagnostic error: Mastocytosis may remain undiagnosed when it is actually present, or it may be diagnosed even though morphological and molecular findings rule out mastocytosis. Well-defined criteria should be used to differentiate mastocytosis from other diseases with a similar clinical presentation.