WHO 2016 systemic mastocytosis criteria

WHO 2016 SM criteria

Apply the Valent 2016 / WHO 2016 systemic mastocytosis diagnostic criteria (Table 1) and return whether the published combination of the major criterion plus at least one minor, or at least three minors, is met. Tryptase >20 ng/mL does not count when an unrelated myeloid neoplasm is present.

LIVE $0.005 USDC GET /api/calc/who_sm

Markdown: /docs/who-sm.md · Canonical: https://magentlab.com/docs/who-sm

Not a medical device. Not a diagnosis, dose, or listing recommendation.

What it computes

When to use

When an agent already has caller-assigned WHO 2016 SM major and minor flags and needs the published criteria result. magent does not diagnose systemic mastocytosis, does not read a biopsy, and does not assay tryptase.

When not to use

Not a medical device.
Not a diagnosis. Criteria met is not a systemic mastocytosis diagnosis without the rest of the WHO 2016 workup.
Not cutaneous mastocytosis only. This tool is WHO 2016 systemic mastocytosis (Table 1) only.
Not ICC 2022. CD30 is not a 2016 minor criterion on this tool.
magent does not read a biopsy or assay tryptase. All flags are caller-assigned.
When associated_myeloid_neoplasm is true, tryptase_gt_20 does not count as a minor (Valent 2016 Table 1 item d is not valid).

Formula

diagnosed iff (major_infiltrates and minor_count ≥ 1) or minor_count ≥ 3; minor_count counts atypical_or_spindle, kit_codon_816, cd2_or_cd25, and tryptase_gt_20 only when associated_myeloid_neoplasm is false (Valent 2016 Table 1 WHO SM). Not a diagnosis. Not cutaneous mastocytosis only. Not ICC 2022

Citation

Title: Mastocytosis: 2016 updated WHO classification and novel emerging treatment concepts
Authors: Valent P, Akin C, Hartmann K, Nilsson G, Reiter A, Hermine O, Sotlar K, Sperr WR, Escribano L, George TI, Kluin-Nelemans HC, Ustun C, Triggiani M, Brockow K, Gotlib J, Orfao A, Schwartz LB, Horny HP, Galli SJ, Arock M, Metcalfe DD
Source: Blood. 2017;129(11):1420-1427 (Epub 2016 Dec 28)
DOI: 10.1182/blood-2016-09-731893

Worked example

Major infiltrates plus KIT codon 816

Given: associated_myeloid_neoplasm=falseatypical_or_spindle=falsecd2_or_cd25=falsekit_codon_816=truemajor_infiltrates=truetryptase_gt_20=false

major_infiltrates true → major true
kit_codon_816 true; remaining minors false; associated_myeloid_neoplasm false → minor_count 1
diagnosed true (major plus ≥1 minor)

Three minors without the major

Given: associated_myeloid_neoplasm=falseatypical_or_spindle=truecd2_or_cd25=truekit_codon_816=truemajor_infiltrates=falsetryptase_gt_20=false

major_infiltrates false
atypical_or_spindle, kit_codon_816, and cd2_or_cd25 true → minor_count 3
diagnosed true (≥3 minors)

Two minors without the major, not SM

Given: associated_myeloid_neoplasm=falseatypical_or_spindle=truecd2_or_cd25=falsekit_codon_816=truemajor_infiltrates=falsetryptase_gt_20=false

major_infiltrates false
atypical_or_spindle and kit_codon_816 true → minor_count 2
diagnosed false (need major plus ≥1 minor, or ≥3 minors)

Major plus tryptase ignored with an associated myeloid neoplasm

Given: associated_myeloid_neoplasm=trueatypical_or_spindle=falsecd2_or_cd25=falsekit_codon_816=falsemajor_infiltrates=truetryptase_gt_20=true

major_infiltrates true; tryptase_gt_20 true; associated_myeloid_neoplasm true
item d is not valid → tryptase_counts false → minor_count 0
diagnosed false (major without a counted minor)

Major plus tryptase without an associated myeloid neoplasm

Given: associated_myeloid_neoplasm=falseatypical_or_spindle=falsecd2_or_cd25=falsekit_codon_816=falsemajor_infiltrates=truetryptase_gt_20=true

major_infiltrates true; tryptase_gt_20 true; associated_myeloid_neoplasm false
tryptase_counts true → minor_count 1
diagnosed true (major plus ≥1 minor)

Also searched as

WHO 2016 systemic mastocytosis
SM diagnostic criteria
KIT codon 816 mastocytosis
Valent 2016 mastocytosis
CD25 mast cells WHO
serum tryptase systemic mastocytosis
WHO SM major minor criteria
atypical spindle mast cells

Try

Opens the live endpoint. Unpaid browser requests show the paywall; agents should send Accept: application/json.

/api/calc/who_sm?major_infiltrates=true&atypical_or_spindle=false&kit_codon_816=true&cd2_or_cd25=false&tryptase_gt_20=false&associated_myeloid_neoplasm=false

Full URL: https://api.magentlab.com/api/calc/who_sm?major_infiltrates=true&atypical_or_spindle=false&kit_codon_816=true&cd2_or_cd25=false&tryptase_gt_20=false&associated_myeloid_neoplasm=false

Call

Expect HTTP 402 until you retry with PAYMENT-SIGNATURE. Incomplete query params return HTTP 400 before any quote or charge.

curl -i -H "Accept: application/json" "https://api.magentlab.com/api/calc/who_sm?major_infiltrates=true&atypical_or_spindle=false&kit_codon_816=true&cd2_or_cd25=false&tryptase_gt_20=false&associated_myeloid_neoplasm=false"

Parameters

Name	Type	Required	Description
`major_infiltrates`	boolean	required	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`	boolean	required	>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.
`kit_codon_816`	boolean	required	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.
`cd2_or_cd25`	boolean	required	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.
`tryptase_gt_20`	boolean	required	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.
`associated_myeloid_neoplasm`	boolean	required	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.

Bulk (POST)

POST the same path with a JSON items array. The first item is the GET unit; each additional item is $0.002. Invalid items return HTTP 400 before settlement.

POST /api/calc/who_sm Max 25 unit_amount + extra_item_amount * (n - 1) extra $0.002 PREVIEW

1 to 25 items. Each item uses the same keys as the GET query parameters.
POST of 1 item costs the same as GET. Lists longer than 25: chunk into multiple POSTs. Extra items still execute; do not pad dummy rows.
The first invalid item fails the whole request (index in the 400 JSON). You are not charged.
HTTP 200 is {count, path, items}. Each items[i] is the GET 200 body for that row.
Catalog misses (empty matches, found=false) stay paid 200s inside that slot.
x402 resource URL is this path plus n and body_sha256. Browsers that prefer text/html get the same paywall as GET; Pay retries POST with the same items.

Example request (fixture)

{
  "items": [
    {
      "associated_myeloid_neoplasm": "false",
      "atypical_or_spindle": "false",
      "cd2_or_cd25": "false",
      "kit_codon_816": "true",
      "major_infiltrates": "true",
      "tryptase_gt_20": "false"
    },
    {
      "associated_myeloid_neoplasm": "false",
      "atypical_or_spindle": "false",
      "cd2_or_cd25": "false",
      "kit_codon_816": "true",
      "major_infiltrates": "true",
      "tryptase_gt_20": "false"
    }
  ]
}

Open bulk paywall →

Opens a two-item fixture on the API host. Unpaid browsers get the same MetaMask paywall as GET; Pay retries POST with those items.

Example 200 (fixture)

{
  "count": 2,
  "path": "/api/calc/who_sm",
  "items": [
    {
      "major": true,
      "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
      "citation": {
        "authors": "Valent P, Akin C, Hartmann K, Nilsson G, Reiter A, Hermine O, Sotlar K, Sperr WR, Escribano L, George TI, Kluin-Nelemans HC, Ustun C, Triggiani M, Brockow K, Gotlib J, Orfao A, Schwartz LB, Horny HP, Galli SJ, Arock M, Metcalfe DD",
        "doi": "10.1182/blood-2016-09-731893",
        "id": "valent-2016",
        "pmid": "28031180",
        "source": "Blood. 2017;129(11):1420-1427 (Epub 2016 Dec 28)",
        "title": "Mastocytosis: 2016 updated WHO classification and novel emerging treatment concepts"
      },
      "formula": "who_sm",
      "formula_expression": "diagnosed iff (major_infiltrates and minor_count ≥ 1) or minor_count ≥ 3; minor_count counts atypical_or_spindle, kit_codon_816, cd2_or_cd25, and tryptase_gt_20 only when associated_myeloid_neoplasm is false (Valent 2016 Table 1 WHO SM). Not a diagnosis. Not cutaneous mastocytosis only. Not ICC 2022",
      "criteria": [
        {
          "factor": "major",
          "met": true
        },
        {
          "factor": "atypical_or_spindle",
          "met": false
        },
        {
          "factor": "kit_codon_816",
          "met": true
        },
        {
          "factor": "cd2_or_cd25",
          "met": false
        },
        {
          "factor": "tryptase_counts",
          "met": false
        },
        {
          "factor": "associated_myeloid_neoplasm",
          "met": false
        },
        {
          "factor": "minor_count_ge_1",
          "met": true
        },
        {
          "factor": "minor_count_ge_3",
          "met": false
        }
      ],
      "minor_count": 1,
      "associated_myeloid_neoplasm": false,
      "atypical_or_spindle": false,
      "cd2_or_cd25": false,
      "diagnosed": true,
      "kit_codon_816": true,
      "major_infiltrates": true,
      "tryptase_counts": false,
      "tryptase_gt_20": false
    },
    {
      "major": true,
      "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
      "citation": {
        "authors": "Valent P, Akin C, Hartmann K, Nilsson G, Reiter A, Hermine O, Sotlar K, Sperr WR, Escribano L, George TI, Kluin-Nelemans HC, Ustun C, Triggiani M, Brockow K, Gotlib J, Orfao A, Schwartz LB, Horny HP, Galli SJ, Arock M, Metcalfe DD",
        "doi": "10.1182/blood-2016-09-731893",
        "id": "valent-2016",
        "pmid": "28031180",
        "source": "Blood. 2017;129(11):1420-1427 (Epub 2016 Dec 28)",
        "title": "Mastocytosis: 2016 updated WHO classification and novel emerging treatment concepts"
      },
      "formula": "who_sm",
      "formula_expression": "diagnosed iff (major_infiltrates and minor_count ≥ 1) or minor_count ≥ 3; minor_count counts atypical_or_spindle, kit_codon_816, cd2_or_cd25, and tryptase_gt_20 only when associated_myeloid_neoplasm is false (Valent 2016 Table 1 WHO SM). Not a diagnosis. Not cutaneous mastocytosis only. Not ICC 2022",
      "criteria": [
        {
          "factor": "major",
          "met": true
        },
        {
          "factor": "atypical_or_spindle",
          "met": false
        },
        {
          "factor": "kit_codon_816",
          "met": true
        },
        {
          "factor": "cd2_or_cd25",
          "met": false
        },
        {
          "factor": "tryptase_counts",
          "met": false
        },
        {
          "factor": "associated_myeloid_neoplasm",
          "met": false
        },
        {
          "factor": "minor_count_ge_1",
          "met": true
        },
        {
          "factor": "minor_count_ge_3",
          "met": false
        }
      ],
      "minor_count": 1,
      "associated_myeloid_neoplasm": false,
      "atypical_or_spindle": false,
      "cd2_or_cd25": false,
      "diagnosed": true,
      "kit_codon_816": true,
      "major_infiltrates": true,
      "tryptase_counts": false,
      "tryptase_gt_20": false
    }
  ]
}

Response

Field	Type	Description
`formula`	string	who_sm
`formula_expression`	string	Valent 2016 Table 1 WHO SM major/minor combination
`diagnosed`	boolean	true iff major_infiltrates and minor_count ≥ 1, or minor_count ≥ 3. Not a diagnosis. Not cutaneous mastocytosis only. Not ICC 2022.
`major`	boolean	Echo of caller-assigned major_infiltrates (Valent 2016 Table 1 major)
`minor_count`	integer	Count of atypical_or_spindle, kit_codon_816, cd2_or_cd25, and tryptase_gt_20 when associated_myeloid_neoplasm is false
`tryptase_counts`	boolean	true iff tryptase_gt_20 and associated_myeloid_neoplasm is false (item d valid)
`major_infiltrates`	boolean	Caller-assigned multifocal dense mast-cell infiltrates flag used
`atypical_or_spindle`	boolean	Caller-assigned >25% atypical or spindle-shaped mast-cell flag used
`kit_codon_816`	boolean	Caller-assigned KIT codon 816 mutation flag used
`cd2_or_cd25`	boolean	Caller-assigned CD2 and/or CD25 mast-cell flag used
`tryptase_gt_20`	boolean	Caller-assigned baseline serum tryptase >20 ng/mL flag used
`associated_myeloid_neoplasm`	boolean	Caller-assigned unrelated myeloid neoplasm flag used; when true, tryptase does not count
`criteria`	array	Per-factor rows with factor and met for major, each counted minor, tryptase_counts, associated_myeloid_neoplasm, and the ≥1 / ≥3 minor thresholds
`citation`	object	Valent 2016 Blood WHO SM citation
`disclaimer`	string	Not-a-device notice

Example JSON

Machine form of the same example. Frozen fixture. Not a live lookup.

{
  "major": true,
  "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
  "citation": {
    "authors": "Valent P, Akin C, Hartmann K, Nilsson G, Reiter A, Hermine O, Sotlar K, Sperr WR, Escribano L, George TI, Kluin-Nelemans HC, Ustun C, Triggiani M, Brockow K, Gotlib J, Orfao A, Schwartz LB, Horny HP, Galli SJ, Arock M, Metcalfe DD",
    "doi": "10.1182/blood-2016-09-731893",
    "id": "valent-2016",
    "pmid": "28031180",
    "source": "Blood. 2017;129(11):1420-1427 (Epub 2016 Dec 28)",
    "title": "Mastocytosis: 2016 updated WHO classification and novel emerging treatment concepts"
  },
  "formula": "who_sm",
  "formula_expression": "diagnosed iff (major_infiltrates and minor_count ≥ 1) or minor_count ≥ 3; minor_count counts atypical_or_spindle, kit_codon_816, cd2_or_cd25, and tryptase_gt_20 only when associated_myeloid_neoplasm is false (Valent 2016 Table 1 WHO SM). Not a diagnosis. Not cutaneous mastocytosis only. Not ICC 2022",
  "criteria": [
    {
      "factor": "major",
      "met": true
    },
    {
      "factor": "atypical_or_spindle",
      "met": false
    },
    {
      "factor": "kit_codon_816",
      "met": true
    },
    {
      "factor": "cd2_or_cd25",
      "met": false
    },
    {
      "factor": "tryptase_counts",
      "met": false
    },
    {
      "factor": "associated_myeloid_neoplasm",
      "met": false
    },
    {
      "factor": "minor_count_ge_1",
      "met": true
    },
    {
      "factor": "minor_count_ge_3",
      "met": false
    }
  ],
  "minor_count": 1,
  "associated_myeloid_neoplasm": false,
  "atypical_or_spindle": false,
  "cd2_or_cd25": false,
  "diagnosed": true,
  "kit_codon_816": true,
  "major_infiltrates": true,
  "tryptase_counts": false,
  "tryptase_gt_20": false
}

Client errors (HTTP 400)

Invalid params return 400 without charge. Shared HTTP 402 and 503 meanings: Payments.

HTTP	Code	When
400	`invalid_flag`	boolean clinical flags must be true or false Returned before settlement; you are not charged.
400	`invalid_items`	POST body must be a JSON object with only an items array Returned before settlement; you are not charged.
400	`invalid_item_count`	items must be an array of 1 to 25 objects Returned before settlement; you are not charged.
400	`invalid_item`	each items entry must be a JSON object Returned before settlement; you are not charged.

Related tools

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MIPSS70 — Sum the Guglielmelli 2018 MIPSS70 (mutation-enhanced international prognostic score system) for transplantation-age primary myelofibrosis and return low (0–1), intermediate (2–4), or high (≥5).

Payment

Unpaid requests return HTTP 402 even if query parameters or POST items are missing or invalid, so CDP and agents can index the path. After a PAYMENT-SIGNATURE, invalid params return HTTP 400 JSON before settlement. magent does not charge. Fix the params, then request a new 402 quote for that complete URL. Catalog misses (empty matches, found=false) are valid paid 200s. Unpaid valid requests return HTTP 402 with a base64 PAYMENT-REQUIRED header. HTTP 503 is not a new quote: retry the same PAYMENT-SIGNATURE. Full handshake and shared payment errors: Payments. Stdio MCP: /docs/mcp.

Guarantees

HTTP 402 is unpaid, including a missing query. After PAYMENT-SIGNATURE, invalid parameters return HTTP 400 before settlement. You are not charged. HTTP 402 never includes the tool JSON.
exact: settlement finishes before the tool (paymentFlow upfront). batch-settlement: verify/deposit before the tool; chargedCumulativeAmount commits after HTTP 2xx. Uncertain or failed settlement fails closed (HTTP 503). Retry the same PAYMENT-SIGNATURE.
HTTP 402 is unpaid only. Do not sign a second authorization because of a 503.
Execution is timeout-bounded and concurrency-capped.
Calculator inputs are stored encrypted for allowlisted operators (Magent Console). They are not in public logs, SSH lookups, catalog, or rollups. Request logs store path without query.