Other carcinoma subtypes, not WHO classified

Topic Completed: 1 March 2012

Minor changes: 21 June 2020

Copyright: 2001-2019,, Inc.

PubMed search: basal-like invasive [title] ductal carcinoma breast

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Monika Roychowdhury, M.D.
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Cite this page: Roychowdhury M. Basal-like. website. Accessed July 10th, 2020.
Definition / general
  • Not in WHO breast classification
  • "Basal like" because tumors have high expression of genes characteristic of basal epithelial cells of normal mammary gland, including CK 5 / 6, CK14, CK15 and CK17
Clinical features
Microscopic (histologic) description
  • High grade or metaplastic morphology, may have medullary features (Am J Surg Pathol 2007;31:501)
  • Also geographic necrosis, pushing borders, stromal lymphocytic response, increased mitotic count
  • Subtypes include pure (negative for S100 and actin) or myoepithelial (S100+ or actin+, Mod Pathol 2007;20:1200)
  • Includes secretory breast carcinomas with ETV6-NTRK3 fusion gene (Mod Pathol 2009;22:291)
  • Core biopsy: solid growth pattern, high nuclear grade, marked lymphocytic infiltrate and geographic necrosis are helpful features, also immunostains (Appl Immunohistochem Mol Morphol 2008;16:411)
Microscopic (histologic) images

Images hosted on other servers:

Various images

H&E and CK14


Various immunostains

Sheet-like growth and high Ki67 index

Tumor without sheet-
like growth but with
high Ki67 index

Normal breast:

CK5 and CK14

CAM 5.2 (CK 8 / 18)
stains luminal epithelium,
CK17 stains basal cells

Contributed by Dr. Semir Vranic, Sarajevo:


Central necrosis


Inflammatory response, periphery

ER negative

CK 5/6




Various images

Various immunostains

Positive stains
Negative stains
  • ER, PR and HER2 (triple negative)
Molecular / cytogenetics description
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