{"entity":{"id":"breast-carcinoma-medullary-pattern","kind":"cancer","name":"Invasive breast carcinoma with medullary pattern (medullary carcinoma)","aka":["Medullary carcinoma","Medullary breast carcinoma","Medullary carcinoma of the breast","Atypical medullary carcinoma","Carcinoma with medullary features","Medullary-like carcinoma"],"tldr":"Medullary carcinoma is a form of breast cancer with high-grade cells growing in sheets and a dense crowd of immune cells around them. It looks alarming under the microscope and is usually triple-negative, yet it has a better outlook than other triple-negative cancers. Since 2019 it is classed as invasive breast cancer with a medullary pattern and treated as triple-negative disease.","summary":"The 2019 WHO classification abandoned medullary carcinoma and atypical medullary carcinoma as separate types because of poor reproducibility, and instead recognises a medullary pattern within invasive breast carcinoma of no special type, treated as one end of the spectrum of tumour-infiltrating lymphocyte-rich triple-negative cancers (Tan 2020). Its histological features are syncytial sheets of high-grade cells, a prominent lymphoplasmacytic infiltrate, a pushing margin and absent gland formation. In 165 triple-negative basal-like carcinomas, prominent inflammation and anastomosing sheets in at least 30 percent of the tumour were each associated with better prognosis, their combination (a simplified medullary-like definition) was present in 17 percent and was an independent prognostic factor with good inter-observer agreement (Modern Pathology 2010). In a Shiraz series of 179 medullary against 3,067 ductal carcinomas, the medullary group had higher grade yet a more favourable clinical outcome (Iranian J Med Sci 2018). Medullary features are over-represented in BRCA1 carriers.\n\nHow it differs from its parent: it is the triple-negative pattern in which the immune infiltrate predicts a good outcome, and its pathology overlaps with the immunomodulatory subtype on the triple-negative page.\n\nHow common: 5.5 percent of one centre's series (Iranian J Med Sci 2018), but with the 2019 definition it is no longer counted separately.\n\nTreatment: as triple-negative breast cancer, following the parent's early and metastatic triple-negative pages (chemotherapy with pembrolizumab in early disease, and the checkpoint and antibody-drug conjugate pathways when advanced); there is no trial in the medullary pattern itself.","asOf":"2026-09-24","wikipedia":"https://en.wikipedia.org/wiki/Medullary_breast_carcinoma","links":[{"label":"Tan 2020, Histopathology: the 2019 WHO classification of tumours of the breast","url":"https://doi.org/10.1111/his.14091"},{"label":"Modern Pathology 2010: medullary features and prognosis in 165 triple-negative basal-like carcinomas","url":"https://doi.org/10.1038/modpathol.2010.123"},{"label":"Iranian J Med Sci 2018: medullary breast carcinoma and invasive ductal carcinoma, 22-year series","url":"https://doi.org/10.30476/ijms.2017.40545"}],"tags":["subtype-page","wave4","breast"],"related":["breast-cancer","tnbc","tnbc-early","invasive-breast-carcinoma-no-special-type","metaplastic-breast-carcinoma"],"cancers":[],"sections":[],"technologies":[],"targets":[],"drugs":["pembrolizumab"],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"group":"breast","burden":"179 of 3,246 patients (5.5 percent) in a 22-year Iranian breast centre series (Iranian J Med Sci 2018); medullary-like features were present in 17 percent of 165 basal-like triple-negative carcinomas (Modern Pathology 2010). Population figures are lower and depend on the definition used.","subtypes":["Invasive carcinoma of no special type with medullary pattern, triple-negative (basal-like) with high lymphocyte infiltrate","Medullary pattern in BRCA1-associated breast cancer","Former atypical medullary carcinoma (partial features)"],"biomarkers":["Triple-negative receptor status with basal markers (CK5/6, CK14, CK17, EGFR)","Tumour-infiltrating lymphocytes (prominent)","BRCA1 germline testing","PD-L1 for metastatic disease"],"standardOfCare":[{"setting":"All stages","approach":"Treated as triple-negative breast cancer on the parent's early and metastatic pages.","refs":["tnbc","tnbc-early","tnbc-metastatic","pembrolizumab"]}],"stateOfArt":[],"history":[],"pipeline":[],"openProblems":[],"parent":"breast-cancer"},"route":"/cancers/breast-carcinoma-medullary-pattern/","neighbours":{"cancer":[{"id":"breast-cancer","kind":"cancer","name":"Breast cancer (all types)","route":"/cancers/breast-cancer/"},{"id":"tnbc-early","kind":"cancer","name":"Early triple-negative breast cancer","route":"/cancers/tnbc-early/"},{"id":"invasive-breast-carcinoma-no-special-type","kind":"cancer","name":"Invasive breast carcinoma of no special type (invasive ductal carcinoma)","route":"/cancers/invasive-breast-carcinoma-no-special-type/"},{"id":"metaplastic-breast-carcinoma","kind":"cancer","name":"Metaplastic breast carcinoma","route":"/cancers/metaplastic-breast-carcinoma/"},{"id":"tnbc-metastatic","kind":"cancer","name":"Metastatic triple-negative breast cancer","route":"/cancers/tnbc-metastatic/"},{"id":"tnbc","kind":"cancer","name":"Triple-negative breast cancer (TNBC)","route":"/cancers/tnbc/"}],"drug":[{"id":"pembrolizumab","kind":"drug","name":"Pembrolizumab","route":"/drugs/pembrolizumab/"}]}}