[Acute mast-cell leukemia. Cytochemical and ultrastructural study, about a particular case (author's transl)].

A case of acute Mast-cell leukemia was studied. A 39 years old female presenting with a brief history of abdominal pain and attacks of flushing; peripheral blood and bone marrow contained up to 60% of poorly differentiated blasts with clumping of deep purpule granules. Peroxydase reaction stains were negative, chloroacetate esterase were strongly positive. Toluidine blue revealed metachromatic stain. Histamine content of the cells was highly greater than normal but nos heparinoid activity could be demonstrated. These abnormal mast-cells have been investigated with the electron microscope; only the dense particular type of granule substructure was found, without any lamellae component. The cells were temptatively classified as "immature" mast-cell. The disease was interpretated as an acute leukemic variety of systemic mastocytosis.