title: Spindle cell metaplastic carcinoma of breast: A clinicopathological and immunohistochemical analysis.
abstract: OBJECTIVE
  To better characterize spindle cell metaplastic carcinoma (SpCMC) of breast, a rare variant of breast cancer that has been classified under the broad rubric of metaplastic carcinoma.
  
  
  METHODS
  We presented herein 19 cases of metaplastic breast carcinoma with dominant spindle cell component. All cases were clinically of breast origin, showed more than 80% spindle morphology, 10 cases exhibited pure spindled morphology, 8 contained invasive ductal carcinoma (IDC) and 1 presented with ductal carcinoma in situ elements.
  
  
  RESULTS
  Immunohistochemical studies showed evidence suggesting myoepithelial and epithelial differentiation as exhibited by immunoreactivity for at least one myoepithelial and epithelial markers in all pure spindle cell components. IDC group showed 21.7% of axillary lymph nodes metastasis rate, whereas the axillary lymph node metastasis rate of the SpCMC group was 1.3%, significantly lower than that of the IDC group (P < 0.001). Immunohistochemical staining of IDC exhibited higher degrees of positivity for ER, PR and Her2 (90, 60 and 30%, respectively) when compared with the SpCMC group, which showed a positive degree of 5.2, 5.2 and 10.5% for ER, PR and Her2, respectively (P < 0.001).
  
  
  CONCLUSIONS
  Based on this series, SpCMC is a rare variant of metaplastic breast carcinoma with the distinct histopathological and immunohistochemical features. The biological behaviors of SpCMC, like axillary lymph node status, were quite different from that of IDC, suggesting that it may act as an independent pathologic subtype. Immunohistochemical analysis of a panel of epithelial and myoepithelial markers could contribute to the pathologic diagnosis of SpCMC.
authors.affiliation: Department of Pathology, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, Chengdu, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Zhu
authors.affiliation: Department of Pathology, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, Chengdu, China.
authors.forename: Ke
authors.initials: K
authors.lastname: Li
authors.affiliation: Department of Pathology, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, Chengdu, China.
authors.forename: Dan-Dan
authors.initials: DD
authors.lastname: Dong
authors.affiliation: Department of Pathology, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, Chengdu, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Fu
authors.affiliation: Department of Pathology, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, Chengdu, China.
authors.forename: Dan-Dan
authors.initials: DD
authors.lastname: Liu
authors.affiliation: Department of Pathology, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, Chengdu, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Pathology, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, Chengdu, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Xu
authors.affiliation: Department of Pathology, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, Chengdu, China.
authors.forename: Lin-Hong
authors.initials: LH
authors.lastname: Song
mesh_terms: D000328:Adult; D000368:Aged; D001365:Axilla; D014408:Biomarkers, Tumor / Q000378:metabolism; D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology*; D002277:Carcinoma / Q000378:metabolism* / Q000473:pathology*; D018270:Carcinoma, Ductal, Breast / Q000473:pathology; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008875:Middle Aged; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D011960:Receptors, Estrogen / Q000378:metabolism; D011980:Receptors, Progesterone / Q000378:metabolism; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; C508053:ERBB2 protein, human
keywords: classification; clinicopathology; immunohistochemistry; invasive ductal carcinoma (IDC); spindle cell metaplastic carcinoma of breast (SpCMC)