Diagnostic Criteria for Systemic Mastocytosis (SM)

If at least 1 major and 1 one minor, or at least 3 minor criteria, are met, the diagnosis of Systemic Mastocytosis (SM) can be established.

Major Criteria: Multifocal dense infiltrates of mast cells in bone marrow or other extracutaneous organ(s) (>15 mast cells in aggregate)

Minor Criteria:

a) Mast cells in bone marrow or other extracutaneous organ(s) show an abnormal morphology (> 25%)

b) C-kit mutation at codon 816 in extracutaneous organ(s). (Activating mutations at codon 816; in most cases, c-kit D816V)

c) Mast cells in bone marrow express CD2 and/or CD25

d) Serum total tryptase > 20 ng/mL (does not count in patients who have associated hematologic clonal non-mast cell lineage disease-type disease)

 

 

References:

  1. Akin C, Metcalfe DD. Systemic mastocytosis. Annu Rev Med. 2004;55:419-32. [Medline]
  2. O’Brien S, Tefferi A, Valent P. Chronic myelogenous leukemia and myeloproliferative disease. Hematology (Am Soc Hematol Educ Program). 2004;:146-62. [Medline]
Created: June 21, 2005
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