# Milan criteria

Milan

Status: LIVE
Price: $0.005 USDC
`GET /api/calc/milan`
HTML: https://magentlab.com/docs/milan
Markdown: https://magentlab.com/docs/milan.md

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

## What it computes

Apply Mazzaferro 1996 Milan criteria and return whether the published size, count, vascular-invasion, and extrahepatic rules all hold (meets_milan).

## When to use

When an agent already has tumor count, largest diameter in centimetres, and preoperative vascular-invasion and extrahepatic flags as in Mazzaferro 1996, and needs the published eligibility result. magent does not interpret imaging.

## When not to use

- Not a medical device.
- Not a transplant listing or organ-allocation order.
- magent does not interpret imaging. tumor_count and largest_cm are caller-assigned.
- This tool is Mazzaferro 1996 Milan criteria only. Not UCSF criteria, not up-to-7, and not OPTN downstaging.

## Formula

```
meets_milan iff no vascular_invasion and no extrahepatic and ((tumor_count == 1 and largest_cm <= 5) or (tumor_count in 2..3 and largest_cm <= 3))
```

## Citation

[Liver transplantation for the treatment of small hepatocellular carcinomas in patients with cirrhosis](https://doi.org/10.1056/NEJM199603143341104)
Mazzaferro V, Regalia E, Doci R, Andreola S, Pulvirenti A, Bozzetti F, Montalto F, Ammatuna M, Morabito A, Gennari L
N Engl J Med. 1996;334(11):693-699
DOI: [10.1056/NEJM199603143341104](https://doi.org/10.1056/NEJM199603143341104)

## Worked example

### Single tumor 5 cm, no invasion, no extrahepatic disease

Given: `extrahepatic=false, largest_cm=5, tumor_count=1, vascular_invasion=false`

1. vascular_invasion is false and extrahepatic is false
2. tumor_count is 1 and largest_cm 5.0 is <= 5
3. meets_milan is true


## Also searched as

- Milan criteria
- Mazzaferro criteria
- HCC transplant criteria
- Milan HCC
- Mazzaferro 1996
- small hepatocellular carcinoma
- Milan listing criteria
- liver transplant HCC size

## Parameters

- `tumor_count` (integer, required): Number of HCC nodules (integer 1-20) as assigned by the caller. A single tumor may be up to 5 cm; two or three nodules must each be 3 cm or less. Four or more nodules fail Milan. magent does not interpret imaging.
- `largest_cm` (number, required): Largest tumor diameter in centimetres (0.1-30). Single tumor meets at 5.0 cm and fails at 5.1. Two or three nodules meet at 3.0 cm and fail at 3.1. magent does not interpret imaging.
- `vascular_invasion` (boolean, required): Preoperative vascular (vessel) invasion as assigned by the caller. true fails Milan (Mazzaferro 1996 excluded preoperative vessel invasion). true or false. magent does not interpret imaging.
- `extrahepatic` (boolean, required): Evident or suspected extrahepatic or lymph-node disease as assigned by the caller. true fails Milan (Mazzaferro 1996 excluded extrahepatic disease). true or false. magent does not interpret imaging.

## 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.

Method: `POST /api/calc/milan`
Max items: 25
Price: unit_amount + extra_item_amount * (n - 1) (unit 5000 atomic, extra 2000 atomic)
Status: 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:

```json
{
  "items": [
    {
      "extrahepatic": "false",
      "largest_cm": "5",
      "tumor_count": "1",
      "vascular_invasion": "false"
    },
    {
      "extrahepatic": "false",
      "largest_cm": "5",
      "tumor_count": "1",
      "vascular_invasion": "false"
    }
  ]
}
```

Human paywall (two-item fixture): https://api.magentlab.com/paywall/bulk/milan

Example 200:

```json
{
  "count": 2,
  "path": "/api/calc/milan",
  "items": [
    {
      "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": "Mazzaferro V, Regalia E, Doci R, Andreola S, Pulvirenti A, Bozzetti F, Montalto F, Ammatuna M, Morabito A, Gennari L",
        "doi": "10.1056/NEJM199603143341104",
        "id": "mazzaferro-1996",
        "pmid": "8594428",
        "source": "N Engl J Med. 1996;334(11):693-699",
        "title": "Liver transplantation for the treatment of small hepatocellular carcinomas in patients with cirrhosis"
      },
      "formula": "milan",
      "formula_expression": "meets_milan iff no vascular_invasion and no extrahepatic and ((tumor_count == 1 and largest_cm <= 5) or (tumor_count in 2..3 and largest_cm <= 3))",
      "criteria": [
        {
          "factor": "no_vascular_invasion",
          "met": true
        },
        {
          "factor": "no_extrahepatic",
          "met": true
        },
        {
          "factor": "size_and_count",
          "met": true
        }
      ],
      "extrahepatic": false,
      "largest_cm": 5.0,
      "meets_milan": true,
      "tumor_count": 1,
      "vascular_invasion": false
    },
    {
      "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": "Mazzaferro V, Regalia E, Doci R, Andreola S, Pulvirenti A, Bozzetti F, Montalto F, Ammatuna M, Morabito A, Gennari L",
        "doi": "10.1056/NEJM199603143341104",
        "id": "mazzaferro-1996",
        "pmid": "8594428",
        "source": "N Engl J Med. 1996;334(11):693-699",
        "title": "Liver transplantation for the treatment of small hepatocellular carcinomas in patients with cirrhosis"
      },
      "formula": "milan",
      "formula_expression": "meets_milan iff no vascular_invasion and no extrahepatic and ((tumor_count == 1 and largest_cm <= 5) or (tumor_count in 2..3 and largest_cm <= 3))",
      "criteria": [
        {
          "factor": "no_vascular_invasion",
          "met": true
        },
        {
          "factor": "no_extrahepatic",
          "met": true
        },
        {
          "factor": "size_and_count",
          "met": true
        }
      ],
      "extrahepatic": false,
      "largest_cm": 5.0,
      "meets_milan": true,
      "tumor_count": 1,
      "vascular_invasion": false
    }
  ]
}
```

## Response fields

- `formula` (string): milan
- `formula_expression` (string): Mazzaferro 1996: no vascular invasion, no extrahepatic disease, and single tumor <=5 cm or 2-3 nodules each <=3 cm
- `meets_milan` (boolean): true only when all published Milan conditions hold. Not a transplant listing.
- `tumor_count` (integer): Echo of the caller-assigned nodule count (1-20)
- `largest_cm` (number): Echo of the caller-assigned largest diameter in centimetres
- `vascular_invasion` (boolean): Echo of the caller-assigned preoperative vascular-invasion flag
- `extrahepatic` (boolean): Echo of the caller-assigned extrahepatic or lymph-node disease flag
- `criteria` (array): Per-factor rows with factor and met; met is true when that Milan condition holds
- `citation` (object): Mazzaferro 1996 N Engl J Med citation
- `disclaimer` (string): Not-a-device notice

## Example JSON

Frozen fixture. Not a live lookup.

```json
{
  "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": "Mazzaferro V, Regalia E, Doci R, Andreola S, Pulvirenti A, Bozzetti F, Montalto F, Ammatuna M, Morabito A, Gennari L",
    "doi": "10.1056/NEJM199603143341104",
    "id": "mazzaferro-1996",
    "pmid": "8594428",
    "source": "N Engl J Med. 1996;334(11):693-699",
    "title": "Liver transplantation for the treatment of small hepatocellular carcinomas in patients with cirrhosis"
  },
  "formula": "milan",
  "formula_expression": "meets_milan iff no vascular_invasion and no extrahepatic and ((tumor_count == 1 and largest_cm <= 5) or (tumor_count in 2..3 and largest_cm <= 3))",
  "criteria": [
    {
      "factor": "no_vascular_invasion",
      "met": true
    },
    {
      "factor": "no_extrahepatic",
      "met": true
    },
    {
      "factor": "size_and_count",
      "met": true
    }
  ],
  "extrahepatic": false,
  "largest_cm": 5.0,
  "meets_milan": true,
  "tumor_count": 1,
  "vascular_invasion": false
}
```

## Errors

- HTTP 400 `invalid_tumor_count`: tumor_count must be an integer from 1 to 20 (Mazzaferro 1996). Returned before settlement; you are not charged.
- HTTP 400 `invalid_largest_cm`: largest_cm must be a number from 0.1 to 30 (Mazzaferro 1996). Returned before settlement; you are not charged.
- HTTP 400 `invalid_flag`: boolean clinical flags must be true or false Returned before settlement; you are not charged.
- HTTP 400 `invalid_items`: POST body must be a JSON object with only an items array Returned before settlement; you are not charged.
- HTTP 400 `invalid_item_count`: items must be an array of 1 to 25 objects Returned before settlement; you are not charged.
- HTTP 400 `invalid_item`: each items entry must be a JSON object Returned before settlement; you are not charged.

Shared HTTP 402 and 503: https://magentlab.com/docs/payments

## Related tools

- [Fong](https://magentlab.com/docs/fong) — Sum the five Fong 1999 preoperative criteria for colorectal liver metastases and return the 0–5 clinical score and whether it is potentially favorable (≤2).

## 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.

- GET the tool with Accept: application/json (do not send Accept: text/html unless you want the human paywall).
- HTTP 402 means you have not paid. Decode the base64 PAYMENT-REQUIRED header. HTTP 503 is not a new quote.
- Sign accepts[0] (exact, EIP-3009) with validBefore = now + maxTimeoutSeconds (600 seconds), or accepts[1] (batch-settlement deposit/voucher) on product GET. Ping and POST {items} stay exact. Magent retries transient facilitator 429/5xx before answering.
- Retry the same URL with PAYMENT-SIGNATURE (base64 JSON of accepted and payload). Magent attaches canonical extensions.bazaar on CDP verify/settle; echoing 402 bazaar is optional.
- Success is HTTP 200 JSON plus PAYMENT-RESPONSE. exact settles before the tool. batch-settlement verifies (and deposit-settles) before the tool and commits the charge after HTTP 2xx. HTTP 503: retry the same PAYMENT-SIGNATURE. Mint a new exact nonce only after a new HTTP 402.

- offered `exact` on eip155:8453: Fixed-price USDC on Base. The buyer authorizes the advertised amount (EIP-3009). magent settles before the tool runs (paymentFlow upfront). extra.assetTransferMethod=eip3009 extra.paymentFlow=upfront.
- offered `batch-settlement` on eip155:8453: Payment-channel vouchers claimed later in batches. Exact stays accepts[0]. Same-path POST {items} is still exact. extra.assetTransferMethod=eip3009 extra.paymentFlow=authorization.

- not offered `upto`: Not offered. Usage-based: buyer authorizes a ceiling, seller settles the actual amount after work. Reserved for a future metered tool. Not for current calculators or code search.

Same-path POST {items} is still scheme exact: one EIP-3009 authorization for GET unit plus $0.002 per extra item. That is not x402 batch-settlement (payment channels / vouchers).

Shared HTTP 402 and 503 table: https://magentlab.com/docs/payments

Stdio MCP (one process per host): https://magentlab.com/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.