# Carcinoma with medullary pattern (medullary breast cancer)

Source: https://onco.cc/cancers/medullary-pattern-breast-carcinoma/  
OnCo record `medullary-pattern-breast-carcinoma` (Cancer). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Medullary breast cancers are high-grade, triple-negative tumours with a sharp border and a heavy immune-cell infiltrate that, despite looking aggressive, do better than ordinary breast cancers of the same grade. They are linked to BRCA1. Pathologists now call them a medullary pattern of common breast cancer rather than a type of their own.

## Summary

Medullary carcinoma was defined by a circumscribed, syncytial growth pattern, high nuclear grade and a dense lymphoplasmacytic infiltrate; because pathologists agreed poorly on the diagnosis and the molecular profile overlaps basal-like carcinoma, the 5th edition of the WHO classification (2019) reclassified it as invasive breast carcinoma of no special type with medullary pattern, alongside the other patterns of common ductal-origin carcinoma (Cserni 2020; Thomas 2023). Its behaviour is better than its grade suggests: among 12,409 patients in 13 International Breast Cancer Study Group trials, 14-year distant recurrence-free interval was 76 percent for 127 medullary against 64 percent for 8,096 invasive ductal tumours (hazard ratio 0.52) and overall survival 66 against 57 percent (0.75); restricted to ER-negative grade 3 tumours the figures were 89 against 63 percent (0.24) and 74 against 54 percent (0.55) (Huober 2012). Medullary tumours are BRCA1-related (odds ratio for BRCA2 versus BRCA1 carrier status 0.25 in the CIMBA pathology series, Mavaddat 2012), and the claudin-low subtype shows frequent medullary differentiation (Prat 2010). The immune infiltrate is the same feature now scored as stromal tumour-infiltrating lymphocytes across triple-negative disease.

## Fields

- Kind: Cancer
- Last checked: 2026-09-24
- Also known as: Medullary carcinoma of the breast; Medullary breast cancer; Invasive carcinoma of no special type with medullary pattern; Atypical medullary carcinoma; Basal-like carcinoma with medullary features
- Tags: breast; tnbc; subtype-page
- Group: breast
- Burden: About 1 percent of breast cancers in trial populations: 127 of 12,409 patients in 13 IBCSG trials were recorded as medullary (Huober 2012). The 2019 WHO classification no longer lists it as a separate type.
- Subtypes: Invasive carcinoma of no special type (ductal) with medullary pattern, the 2019 WHO term; Classic medullary carcinoma by the older strict criteria; Atypical medullary carcinoma (older term for tumours meeting some criteria)
- Biomarkers: Triple-negative receptor status with grade 3; Dense lymphoplasmacytic infiltrate (high stromal tumour-infiltrating lymphocytes); Germline BRCA1 (medullary tumours are BRCA1-related)

## Sections of this record

The page is a hub with ten sections in reading order; large sections have their own page. The same plan as JSON: https://onco.cc/api/v1/cancers/medullary-pattern-breast-carcinoma/sections.json

- Overview (on the hub): The TL;DR, the family this cancer belongs to, the organ, who gets it and what the state of the art is. https://onco.cc/cancers/medullary-pattern-breast-carcinoma/#overview
- What it is (on the hub): Anatomy, the subtypes and how they differ, how it is staged, and where advanced disease spreads. https://onco.cc/cancers/medullary-pattern-breast-carcinoma/#what-it-is [3 subtypes]
- Finding it (on the hub): How it shows itself, how it is confirmed, what screening exists, and the biomarkers clinicians test for. https://onco.cc/cancers/medullary-pattern-breast-carcinoma/#finding-it [3 biomarkers]
- Treating it (on the hub): The standard of care by setting, the medicines, surgery and radiotherapy named in it, and the regimens behind them. https://onco.cc/cancers/medullary-pattern-breast-carcinoma/#treating-it [1 setting]
- Evidence (on the hub): Trials recruiting now, the landmark trials, the key papers and what they mean, the latest literature, and the milestones year by year. https://onco.cc/cancers/medullary-pattern-breast-carcinoma/#evidence [1 trial]
- The science (on the hub): The molecular landscape: the targets and how often each appears, the pathways, the mechanics stages and the preclinical models. https://onco.cc/cancers/medullary-pattern-breast-carcinoma/#science [1 target]
- Where you are (own page): Cases by country, the UK and NHS pathway and other country lenses, and the expert centres with trials on record. https://onco.cc/cancers/medullary-pattern-breast-carcinoma/where-you-are/
- Living with it (on the hub): The decisions you may face, the aids that walk through them, the warnings on record, the first sixty days and the questions to ask. https://onco.cc/cancers/medullary-pattern-breast-carcinoma/#living-with-it [8 questions]
- What is coming (own page): Everything in development, the open problems and what is being done about them, the roadmaps, and what changed on this record. https://onco.cc/cancers/medullary-pattern-breast-carcinoma/coming/
- Data (own page): Every connected record, the notes, the JSON, Markdown and RDF twins, and where the record came from and when it was checked. https://onco.cc/cancers/medullary-pattern-breast-carcinoma/data/ [6 connected records]

## Standard of care

- Early disease: As for triple-negative disease of no special type, including germline testing; the medullary pattern is recorded because of its better prognosis but does not change the NICE pathway. ([KEYNOTE-522](https://onco.cc/trials/keynote-522/), [Germline (hereditary) testing](https://onco.cc/technologies/germline-testing/), [Tumour-infiltrating lymphocytes (TILs)](https://onco.cc/terms/tils/))

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Medullary_breast_carcinoma
- Huober, Ann Oncol 2012: prognosis of medullary breast cancer in 13 IBCSG trials: https://doi.org/10.1093/annonc/mds105
- Cserni, Pathologica 2020: histological type and typing of breast carcinomas and WHO classification changes: https://doi.org/10.32074/1591-951x-1-20
- Thomas, NPJ Breast Cancer 2023: rare subtypes of triple-negative breast cancer: https://doi.org/10.1038/s41523-023-00554-x
- Mavaddat, Cancer Epidemiol Biomarkers Prev 2012: pathology of breast cancers in BRCA1 and BRCA2 carriers (CIMBA): https://doi.org/10.1158/1055-9965.epi-11-0775
- Prat, Breast Cancer Res 2010: phenotypic and molecular characterisation of the claudin-low intrinsic subtype: https://doi.org/10.1186/bcr2635

## Connected records

- cancers: [BRCA-associated triple-negative breast cancer](https://onco.cc/cancers/brca-associated-tnbc/), [Immunomodulatory triple-negative breast cancer (IM)](https://onco.cc/cancers/tnbc-immunomodulatory/), [Metaplastic breast carcinoma](https://onco.cc/cancers/metaplastic-breast-carcinoma/), [Triple-negative breast cancer (TNBC)](https://onco.cc/cancers/tnbc/)
- targets: [BRCA1 / BRCA2 (HRD)](https://onco.cc/targets/brca/)
- terms: [Basal-like breast cancer](https://onco.cc/terms/basal-like/), [Germline BRCA testing criteria for triple-negative breast cancer (UK)](https://onco.cc/terms/germline-brca-testing-criteria-tnbc/), [Tumour-infiltrating lymphocytes (TILs)](https://onco.cc/terms/tils/)
- trials: [KEYNOTE-522](https://onco.cc/trials/keynote-522/)
- technologies: [Germline (hereditary) testing](https://onco.cc/technologies/germline-testing/)

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JSON: https://onco.cc/api/v1/entities/medullary-pattern-breast-carcinoma.json