ICC and WHO 22 diagnostic criteria for the diagnosis of SM
| ICC Presence of the major criterion is sufficient for diagnosis. In the absence of the major criterion, at least 3 of the 4 minor criteria must be present. . |
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| Major criterion Multifocal dense infiltrates of tryptase- and/or CD117-positive MCs (≥15 MCs in aggregates) detected in sections of BM and/or other extracutaneous organ(s) |
| Minor criteria a. In BM biopsy or in section of other extracutaneous organs >25% of MCs are spindle-shaped or have an atypical immature morphology b. MCs in BM, PB, or other extracutaneous organs express CD25, CD2, and/or CD30, in addition to MC markers c. KIT D816V mutation or other activating KIT mutation detected in BM, PB, or other extracutaneous organs d. Elevated serum tryptase level, persistently >20 ng/mL In cases of SM-AMN, an elevated tryptase does not count as an SM minor criterion. |
| WHO Requires at least 1 major criterion and 1 minor or 3 minor criteria. . |
| Major criterion Multifocal dense infiltrates of MCs (≥15 MCs in aggregates) in BM biopsies and/or in sections of other extracutaneous organ(s) |
| Minor criteria a. >25% of all MCs are atypical cells (type I or type II) on BM smears or are spindle-shaped in MC infiltrates detected on sections of visceral organs b. KIT point mutation at codon 816 in the BM or another extracutaneous organ c. MCs in BM, blood, or another extracutaneous organ exhibit CD2 and/or CD25 d. Baseline serum tryptase level >20 ng/mL In case of an unrelated myeloid neoplasm, item d is not valid as an SM criterion. |
| ICC Presence of the major criterion is sufficient for diagnosis. In the absence of the major criterion, at least 3 of the 4 minor criteria must be present. . |
|---|
| Major criterion Multifocal dense infiltrates of tryptase- and/or CD117-positive MCs (≥15 MCs in aggregates) detected in sections of BM and/or other extracutaneous organ(s) |
| Minor criteria a. In BM biopsy or in section of other extracutaneous organs >25% of MCs are spindle-shaped or have an atypical immature morphology b. MCs in BM, PB, or other extracutaneous organs express CD25, CD2, and/or CD30, in addition to MC markers c. KIT D816V mutation or other activating KIT mutation detected in BM, PB, or other extracutaneous organs d. Elevated serum tryptase level, persistently >20 ng/mL In cases of SM-AMN, an elevated tryptase does not count as an SM minor criterion. |
| WHO Requires at least 1 major criterion and 1 minor or 3 minor criteria. . |
| Major criterion Multifocal dense infiltrates of MCs (≥15 MCs in aggregates) in BM biopsies and/or in sections of other extracutaneous organ(s) |
| Minor criteria a. >25% of all MCs are atypical cells (type I or type II) on BM smears or are spindle-shaped in MC infiltrates detected on sections of visceral organs b. KIT point mutation at codon 816 in the BM or another extracutaneous organ c. MCs in BM, blood, or another extracutaneous organ exhibit CD2 and/or CD25 d. Baseline serum tryptase level >20 ng/mL In case of an unrelated myeloid neoplasm, item d is not valid as an SM criterion. |
BM, bone marrow; PB, peripheral blood.