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Clinical calculator summary

Gleason Score and WHO/ISUP Grade Group converter

A strict lookup that converts an ordered pair of pathologist-reported Gleason patterns 3, 4, or 5 to its Gleason score and WHO/ISUP Grade Group.

Evidence-based context for fast calculator use

Purpose:
To reproduce the contemporary nine-pair Gleason score-to-Grade Group mapping without independently grading tissue or assigning clinical risk.
Population:
Pathology-reported conventional prostatic adenocarcinoma with an assigned ordered Gleason pattern pair and no grading exclusion.
Factors:
First pathologist-reported pattern, Second pathologist-reported pattern, Specimen-specific pathology assignment
Reference:
2014 ISUP consensus; WHO 2022; ICCR 2024; CAP 2023.
HomeGleason Score & WHO/ISUP Grade Group
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Gleason Score & WHO/ISUP Grade Group

Clinical Context & Background

This converter accepts the two ordered Gleason patterns already assigned by a pathologist and maps them to the Gleason score and contemporary WHO/ISUP Grade Group. Enter the first and second patterns exactly as reported. Order matters: 3 + 4 and 4 + 3 both sum to 7 but map to different Grade Groups. If only one pattern is present, pathology repeats that pattern when assigning the score.
Rules for deriving the ordered pair differ between needle biopsy and prostatectomy specimens. Biopsy grading uses the primary pattern and the highest remaining pattern under biopsy-specific rules; prostatectomy grading uses specimen-specific primary and secondary pattern rules. This calculator does not inspect or grade tissue, derive patterns from percentages, combine unrelated cores, or assign an overall/global grade. The pathology report and pathology review control the pair entered.
Do not use this converter for cancer with significant treatment effect, non-adenocarcinoma, pure intraductal carcinoma of the prostate (IDC-P), atypical intraductal proliferation (AIP), or indeterminate/unassigned patterns. It does not assign overall clinical risk or treatment.
Primary Source EvidenceEpstein JI, Egevad L, Amin MB, et al. 2014 ISUP Consensus Conference, Am J Surg Pathol. 2016;40:244-252. WHO Classification of Tumours Editorial Board. Urinary and Male Genital Tumours, 5th ed., 2022. ICCR Prostate Core Needle Biopsy Reporting Guide, 2nd ed., 2024. CAP Prostate Needle Biopsy Protocol, v1.1.0.0, 2023.
Formula Logic
Explicit lookup of the ordered pathology-reported pair: 3+3->6/GG1; 3+4->7/GG2; 4+3->7/GG3; 4+4, 3+5, or 5+3->8/GG4; 4+5 or 5+4->9/GG5; 5+5->10/GG5.

Reference Data

Ordered Gleason patternsGleason scoreWHO/ISUP Grade Group
3 + 36Grade Group 1
3 + 47Grade Group 2
4 + 37Grade Group 3
4 + 48Grade Group 4
3 + 58Grade Group 4
5 + 38Grade Group 4
4 + 59Grade Group 5
5 + 49Grade Group 5
5 + 510Grade Group 5

Clinical Workflow

Use, Interpret, And Continue The Patient Pathway

Expand for workflow guidance, limitations, examples, and related next steps.

When To Use

  • Use only after a pathology report has assigned both ordered Gleason patterns.
  • Use for a direct score and WHO/ISUP Grade Group conversion, not for tissue interpretation.

How To Interpret

  • Read the ordered pair, Gleason score, and WHO/ISUP Grade Group together.
  • Preserve order because 3 + 4 is Grade Group 2 while 4 + 3 is Grade Group 3.

What To Do Next

  • Confirm the entered pair and specimen context against the signed pathology report.
  • Request pathology clarification when patterns are absent, indeterminate, or affected by an exclusion.
  • Perform clinical risk assessment separately using the full clinical and pathologic context.

Limitations

  • Does not independently grade tissue, infer patterns from percentages, or combine unrelated cores.
  • Does not assign an overall/global grade, clinical risk category, prognosis, or treatment.
  • Excludes significant treatment effect, non-adenocarcinoma, pure IDC-P/AIP, and indeterminate or unassigned patterns.

Validated Population

Source-defined contemporary WHO/ISUP mapping for pathology-assigned Gleason patterns 3, 4, and 5 in prostatic adenocarcinoma.

Order-sensitive conversion

A pathology-reported pair of 3 + 4 maps to Gleason score 7, Grade Group 2; 4 + 3 maps to Gleason score 7, Grade Group 3.

Calculation verification history

Verified

  1. : Production browser revalidation

    • Three source-backed Gleason cases passed through visible production controls at 3+3, 3+4, and 4+3, preserving order-sensitive Grade Groups.
    • The former numeric-select form-boundary failure was absent; no unexpected N/A, literal undefined value, stale control, or browser-console error was observed.
    Download latest production check (Excel)

    Case-level evidence is retained in validation/browser-revalidation/prostate-gleason-score-2026-08-03.json.

  2. : Local browser remediation verified; production retest pending

    • Updated the public select adapter to accept the exact numeric 3/4/5 option values emitted by the shared browser form while preserving the strict ordered-pair engine.
    • All nine valid ordered pairs and one missing-field/reset/repeat case passed through visible browser controls.
    • The production finding remains open until deployment and public revalidation.

    Local diagnostic evidence is retained in validation/browser-production/prostate-gleason-score.local-remediation.json.

  3. : Production browser validation

    • Ten source-backed cases were exercised on the public production route through visible browser controls; 0/10 case records passed their expected-versus-observed assertions across 12 visible submissions.
    • Overall browser status: failed-calculation-ui-and-console. critical: Every one of the nine valid visible ordered pattern pairs renders N/A / Invalid Input even though both selects visibly retain the intended patterns. The production form supplies numeric option values while the normalization boundary accepts only strings. | medium: Production emitted minified React error #418 during the route load.
    • Case-level inputs, expected and observed results, reset/repeat behavior, failure reproductions, and console evidence are retained in the production-browser evidence record.

    Case-level production evidence is retained in validation/browser-production/prostate-gleason-score.json.

  4. : Full validation test

    • Verified all nine ordered pattern pairs against literal fixtures, including score, WHO/ISUP Grade Group, 3+4 versus 4+3 ordering, trace, exact UI serialization, immutability, broad malformed-input rejection, and no-default/reset behavior.

  5. : Correction history

    • Replaced permissive arithmetic thresholds with a strict nine-pair whitelist and removed both defaults.
    • Relabeled the preserved public inputs as the two ordered patterns already reported by pathology and removed unsupported clinical-risk and treatment labels.

Verification confirms the calculator implementation against the cited model; it is not independent clinical validation, regulatory approval, or medical advice.

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Frequently Asked Questions

Which values can I enter?

Enter exactly two ordered patterns from the pathology report. Each must be Pattern 3, 4, or 5.

Does the order of the patterns matter?

Yes. For example, 3 + 4 and 4 + 3 both total 7, but map to Grade Groups 2 and 3, respectively.

What if the pathology report contains only one pattern?

For a uniform grade, pathology repeats the pattern when assigning the Gleason score. Enter the ordered pair exactly as reported; do not infer or duplicate a pattern independently.

Does this result determine prostate cancer risk or treatment?

No. It only converts a pathology-assigned ordered pattern pair to a score and Grade Group. Clinical risk and treatment require separate assessment of the complete case.

Evidence-based oncology decision support. Verify with clinical guidelines.