Mastocytosis is a heterogeneous group of disorders characterized by a clonal proliferation and accumulation of mast cells in one or more organ, primarily in the skin and bone marrow. The clinical spectrum of the disease varies from relatively benign forms with isolated skin lesions to very aggressive variants with extensive systemic involvement and poor prognosis. The growth and proliferation of clonal mast cells is caused by an activating mutation of the tyrosine kinase receptor Kit for Stem Cell Factor, the main growth factor for mast cells. Clinical symptoms are related to mast-cell mediator release, to the tissue mast cell infiltration or both. The degree of infiltration and cell activation determines the highly variable clinical and morphological features. Current treatment of mastocytosis includes symptomatic, antimediator drugs and cytoreductive targeted therapies
