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mammary metaplastic carcinoma

Sunday 8 July 2012

Metaplastic carcinoma of the breast, metaplasic breast carcinoma; Metaplastic carcinoma of the breast

Definition: Metaplastic breast carcinoma is a rare and aggressive histologic type of breast cancer, preferentially displaying a triple-negative phenotype.

Metaplasic carcinoma of the breast was initially described by Huvos in 1974. It is a rare and aggressive entity characterized by the presence of mesenchymal and epithelial components.

Metaplasic carcinoma is a rare and aggressive disease. Expression of both tumor cytokeratin 5/6 CK5/6 and p63 is associated with a worse outcome. (27424438)


- Metaplastic carcinoma of the breast

Digital cases

- JRC:5046 : Metaplastic carcinoma of the breast.
- JRC:5047 : Metaplastic carcinoma of the breast.
- JRC:5048 : Metaplastic carcinoma of the breast.

The diversity of histologic features of metaplastic breast carcinomas is reflected at the transcriptomic level, and an association between molecular subtypes and histology was observed.

Differential diagnosis: mammary biphasic lesions

- adenomyoepithelioma
- mammary fibroadenomas

  • mammary juvenile fibroadenoma

- mammary hamartoma
- metaplastic mammary carcinoma
- phyllodes tumor
- pleomorphic adenoma
- gynecomastia
- pubertal macromastia


- p63 is sensitive and specific for metaplastic carcinoma.
- Negative : ER-, PR-, HER2-, mammaglobin-

Molecular biology

BRCA1-like genomic profiles are found only in a subset (31%) of metaplastic breast cancers, and are not associated with a specific molecular or histologic subtype.

See also

- mammary carcinomas

Open references

- Metaplastic breast carcinomas display genomic and transcriptomic heterogeneity. Weigelt B, Ng CK, Shen R, Popova T, Schizas M, Natrajan R, Mariani O, Stern MH, Norton L, Vincent-Salomon A, Reis-Filho JS. Mod Pathol. 2015 Mar;28(3):340-51. doi : 10.1038/modpathol.2014.142 PMID: 25412848 (Free)