WHO Criteria for Mast Cell Leukemia

 

Criteria for the diagnosis of mast cell leukemia:

(1) meets the criteria for systemic mastocytosis

(2) biopsy shows a diffuse infiltration by atypical, immature mast cells, usually showing an interstitial pattern

(3) bone marrow aspirate shows >= 20% mast cells

 

Percent Mast Cells in Peripheral Blood	Diagnosis
>= 10%	mast cell leukemia
< 10%	aleukemic mast cell leukemia

 

where:

• The percent bone marrow mast cell is one of the minor criteria for systemic mastocytosis.