Guide to systemic mastocytosis Criteria for diagnosis: at least 1 major and 1 minor or 3 minor criteria present Major: • Multifocal dense infiltrates of MC (2 15 MCs in aggregates) in BM or other tissues. Minor: • >25% of all MCs are atypical on BM aspirate or spindle shaped on tissue sections • KIT mutation at codon 816 • MCs express CD2 and/or CD25 • Serum tryptase level >20 ng/mL (unless an AHN is present) B- and C-Findings: B-findings: mediator release • MCs in BM >30% and serum tryptase > 200 ng/ml • Hypercellular BM + dysmyelopoiesis, w/o cytopenias or meeting criteria for MDS or MPN • Organomegaly without organ dysfunction C-Findings: possible tissue damage • Cytopenia (ANC<1000, Hb <10, Plt < 100k) • Hepatomegaly with ascites/impaired liver function • Palpable splenomegaly with hypersplenism • Malabsorption with hypoalbuminemia • Skeletal lesions Dr. Laura Brown @lauraebrown #systemic #mastocytosis #hemepath #pathology #algorithm #diagnosis #clinical
