Immunohistochemistry

Malignancy

Myoepithelial cell

Medicine

Salivary gland

Adenoid cystic carcinoma

Pleomorphic adenoma

Histogenesis

Carcinoma

Pathology

Histopathology

Breast lesions with a prominent myoepithelial cell component constitute a heterogeneous group of benign and malignant neoplastic proliferations. These lesions are often dual epithelial–myoepithelial, but may be purely myoepithelial cell in nature. Benign epithelial–myoepithelial lesions typically maintain the morphology and immunophenotype of the normal bilayer epithelial myoepithelial structures. However, the distinction between the two cell components is not always clear‐cut in malignant lesions in which the histogenesis of myoepithelial cells remains uncertain. Neoplastic biphasic epithelial–myoepithelial lesions of the breast include adenomyoepithelioma (AME), pleomorphic adenoma and adenoid cystic carcinoma. Four histological patterns of classical AME have been described: tubular, lobulated, spindle‐cell and adenosis variants. Overlapping patterns occur and some AMEs display an intraductal papillary pattern that may represent a fifth variant. AME can be benign or malignant. Classical AME may show atypica...

Adenomyoepithelioma of the breast: a proposal for classification