title: Mast cell leukemia.
abstract: Mast cell leukemia (MCL) is a very rare form of aggressive systemic mastocytosis accounting for < 1% of all mastocytosis. It may appear de novo or secondary to previous mastocytosis and shares more clinicopathologic aspects with systemic mastocytosis than with acute myeloid leukemia. Symptoms of mast cell activation-involvement of the liver, spleen, peritoneum, bones, and marrow-are frequent. Diagnosis is based on the presence of ≥ 20% atypical mast cells in the marrow or ≥ 10% in the blood; however, an aleukemic variant is frequently encountered in which the number of circulating mast cells is < 10%. The common phenotypic features of pathologic mast cells encountered in most forms of mastocytosis are unreliable in MCL. Unexpectedly, non-KIT D816V mutations are frequent and therefore, complete gene sequencing is necessary. Therapy usually fails and the median survival time is < 6 months. The role of combination therapies and bone marrow transplantation needs further investigation.
authors.affiliation: Centre de Référence des Mastocytoses, Faculté de Médecine et Assistance Publique-Hopitaux de Paris (AP-HP) Necker-Enfants Malades, Paris, France.
authors.forename: Sophie
authors.initials: S
authors.lastname: Georgin-Lavialle
authors.forename: Ludovic
authors.initials: L
authors.lastname: Lhermitte
authors.forename: Patrice
authors.initials: P
authors.lastname: Dubreuil
authors.forename: Marie-Olivia
authors.initials: MO
authors.lastname: Chandesris
authors.forename: Olivier
authors.initials: O
authors.lastname: Hermine
authors.forename: Gandhi
authors.initials: G
authors.lastname: Damaj
mesh_terms: D018450:Disease Progression; D006801:Humans; D007946:Leukemia, Mast-Cell / Q000401:mortality / Q000473:pathology* / Q000628:therapy*; D008407:Mast Cells / Q000473:pathology*; D034721:Mastocytosis, Systemic / Q000401:mortality / Q000473:pathology / Q000628:therapy