Surgical Pathology Criteria

Metaplastic Carcinoma of the Breast

Differential Diagnosis

 

 

Metaplastic Carcinoma Phyllodes Tumor
Spindled component may be positive for high molecular weight keratin or p63 Stromal component negative for high molecular weight keratin and p63
Epithelial component is malignant Epithelial component is benign
Squamous differentiation may be present No squamous differentiation

 

 

 

 

Metaplastic Carcinoma of the Breast with Mesenchymal Differentiation Carcinoma of the Breast with Osteoclast-like Giant Cells
Sarcomatous (malignant) stroma Only giant cells, no neoplastic stroma
May form osteoid (osteosarcoma) No osteoid
Other metaplastic carcinomas with non-mesenchymal differentation would not be confused with carcinomas with osteoclast-like giant cells

 

Metaplastic Carcinoma Adenomyoepithelioma
Glandular component, if present, is histologically malignant, except in low grade spindle cell metaplastic carcinoma Epithelial component is histologically bland
Stromal component may be bland or histologically malignant Stroma is histologically bland
Stromal component may resemble a variety of sarcomas or low grade fibrous proliferation Stroma shows myoepithelial differentiation only
Squamous differentiation may be present No squamous differentiation

Stanford Medicine Resources:

Footer Links: