{"uid":"cap_SL1HxRzhJCKdbaqmeLXZx","slug":"who-2016-systemic-mastocytosis-criteria-calculator-magent-dc49b4ad","name":"WHO 2016 Systemic Mastocytosis Criteria Calculator (magent)","description":"WHO 2016 systemic mastocytosis (Valent 2016 Table 1). Met when major infiltrates (≥15 mast cells in aggregates in BM or extracutaneous organ) plus ≥1 minor, or ≥3 minors. Minors: >25% atypical/spindle mast cells, KIT codon 816, CD2 and/or CD25, tryptase >20 ng/mL (not valid with an unrelated myeloid neoplasm). Not a diagnosis. Not cutaneous mastocytosis only. Not ICC 2022. magent does not read a biopsy or assay tryptase.","url":"https://api.magentlab.com/api/calc/who_sm","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET","HEAD","DELETE"],"type":"string"},"headers":{"type":"object","additionalProperties":{"type":"string"}},"queryParams":{"type":"object","required":["major_infiltrates","atypical_or_spindle","kit_codon_816","cd2_or_cd25","tryptase_gt_20","associated_myeloid_neoplasm"],"properties":{"cd2_or_cd25":{"type":"boolean","description":"Mast cells in bone marrow, blood, or another extracutaneous organ exhibit CD2 and/or CD25, as assigned by the caller (Valent 2016 Table 1 minor c). true or false. magent does not phenotype mast cells."},"kit_codon_816":{"type":"boolean","description":"KIT point mutation at codon 816 in bone marrow or another extracutaneous organ, as assigned by the caller (Valent 2016 Table 1 minor b). true or false. magent does not sequence KIT."},"tryptase_gt_20":{"type":"boolean","description":"Baseline serum tryptase >20 ng/mL as assigned by the caller (Valent 2016 Table 1 minor d). Does not count when associated_myeloid_neoplasm is true. true or false. magent does not assay tryptase."},"major_infiltrates":{"type":"boolean","description":"Multifocal dense infiltrates of mast cells (≥15 MCs in aggregates) in bone marrow or another extracutaneous organ, as assigned by the caller (Valent 2016 Table 1 major). true or false. magent does not read a biopsy."},"atypical_or_spindle":{"type":"boolean","description":">25% atypical (type I/II) or spindle-shaped mast cells in infiltrates or smears, as assigned by the caller (Valent 2016 Table 1 minor a). true or false. magent does not read slides."},"associated_myeloid_neoplasm":{"type":"boolean","description":"Unrelated myeloid neoplasm present as assigned by the caller (Valent 2016 Table 1: item d is not valid). When true, tryptase_gt_20 does not count as a minor. true or false. magent does not diagnose a myeloid neoplasm."}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.005","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.005/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_XZSqz-35uWA5fHYC1mB4R","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.005","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Evaluates caller-assigned boolean findings against WHO 2016 (Valent 2016 Table 1) criteria to determine whether systemic mastocytosis diagnostic criteria are met.","exampleAgentPrompt":"Does this patient meet WHO 2016 systemic mastocytosis criteria? They have major bone marrow infiltrates, more than 25% atypical spindle mast cells, a KIT codon 816 mutation, and CD25 expression — no associated myeloid neoplasm, and tryptase is above 20.","exampleUseCases":[{"title":"SM workup after bone marrow biopsy","prompt":"A patient's bone marrow biopsy shows multifocal dense mast cell infiltrates and over 25% spindle-shaped mast cells. KIT D816V is positive, CD25 is expressed, and baseline tryptase is 32 ng/mL. No concurrent myeloid neoplasm. Do they meet WHO 2016 systemic mastocytosis criteria?"},{"title":"Evaluating SM criteria with concurrent AML","prompt":"This patient has KIT codon 816 mutation and CD2 expression on mast cells, but also has an associated AML diagnosis — so tryptase elevation shouldn't count as a minor criterion. Major infiltrates are absent. Do the remaining findings satisfy WHO 2016 SM criteria?"},{"title":"Confirming three-minor rule without major criterion","prompt":"No major bone marrow infiltrates on biopsy, but the patient has atypical spindle mast cells exceeding 25%, a KIT codon 816 point mutation, and CD25 positivity. Tryptase is 18 — not elevated. No myeloid neoplasm. Does this satisfy the WHO 2016 systemic mastocytosis three-minor rule?"}],"resultDescription":"Returns whether WHO 2016 systemic mastocytosis criteria are met (true/false), along with the count and identity of satisfied major and minor criteria, applying the rule that tryptase >20 does not count as a minor when an associated myeloid neoplasm is present.","failureModes":["Missing required boolean parameters returns a validation error","All inputs false returns criteria not met with zero minors","tryptase_gt_20 true with associated_myeloid_neoplasm true silently excluded from minor count (expected behavior, not an error)","Misclassification risk if caller assigns biopsy/lab findings incorrectly — the API does not validate clinical data"],"whenToPreferThis":"Use this endpoint when you have already gathered structured boolean findings from clinical reports (biopsy, flow cytometry, KIT sequencing, tryptase assay) and need to apply the WHO 2016 (Valent 2016 Table 1) algorithm programmatically. Prefer it over manual rule application whenever automating hematology diagnostic workflows. Not appropriate for ICC 2022 criteria, cutaneous mastocytosis only, or when raw lab values or pathology images need to be interpreted — the caller must pre-assign all boolean inputs.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T07:14:15.026Z","isFirstParty":false}