[Mastocytosis: revisited with new cytogenetic data]

Mastocytosis is a heterogenous disorder due to abnormal proliferation and infiltration of mast cells in different tissues, primarily the skin and the bone marrow. Cutaneous mastocytosis is often benign and regresses spontaneously. Systemic mastocytosis is a chronic disease in which some types are indolent but other types such as mast cell leukemia are very aggressive. Pathogenesis of systemic mastocytosis involves a somatic mutation of the gene coding for the c-kit receptor, the most frequent mutation being D816V. Diagnostic criteria have been established by the WHO using histopathological, molecular and biochemical parameters. Treatment of systemic mastocytosis remains a challenge for the clinician due to variability and complexity of the disease. There is, in addition, a lack of a standard and efficient treatment. New targeted therapies with tyrosine kinase inhibitors directed against the c-kit receptor are currently being studied, with the purpose to act specifically on the " primum movens "of the disease. The current review provides an overview of pathogenesis, clinical presentation, diagnosis and classification of cutaneous and systemic mastocytosis. We also discuss the prognosis and the different treatments currently available according to the sub-type of mastocytosis.