title: Myoepithelial carcinoma arising in an adenomyoepithelioma of the breast: case report with immunohistochemical and mutational analysis.
abstract: Adenomyoepithelioma (AME) of the breast is an uncommon tumor characterized by biphasic proliferation of both epithelial and myoepithelial cells. In rare instances, the epithelial, the myoepithelial or both components of an AME may become malignant. Described herein is the case of a 69-year-old woman who presented with myoepithelial carcinoma of the breast in an AME. Malignancy of myoepithelial component (MEC) was evidenced by the presence of cytological atypia, high mitotic rate, necrosis and local invasion. Immunohistochemical study demonstrated strong expression of P53 and phosphorylated extracellular signal-regulated kinase 1/2 in MEC. Laser capture microdissection technique and mutational analysis further revealed point mutation of the p53 gene (T-->G transversion at codon 270) in this population, but not in glandular epithelial cells or adjacent normal ductal epithelium. No mutations in exons 1 and 2 of the K-, H-, and N-ras genes were identified in any of the neoplastic component. To the authors' knowledge this is the first report of a mutation in the p53 gene in a malignant AME of the breast.
authors.affiliation: Department of Pathology, Wakayama Medical University, Kimiidera, Wakayama, Japan. hanbo@wakayama-med.ac.jp
authors.forename: Bo
authors.initials: B
authors.lastname: Han
authors.forename: Ichiro
authors.initials: I
authors.lastname: Mori
authors.forename: Misa
authors.initials: M
authors.lastname: Nakamura
authors.forename: Xiaojuan
authors.initials: X
authors.lastname: Wang
authors.forename: Takashi
authors.initials: T
authors.lastname: Ozaki
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Nakamura
authors.forename: Kennichi
authors.initials: K
authors.lastname: Kakudo
mesh_terms: D000368:Aged; D001483:Base Sequence; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D003528:Carcinoma, Adenoid Cystic / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007834:Lasers; D042282:Microdissection; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D009154:Mutation; D009208:Myoepithelioma / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D009378:Neoplasms, Multiple Primary / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D016133:Polymerase Chain Reaction; D016159:Tumor Suppressor Protein p53 / Q000235:genetics* / Q000378:metabolism
chemical_list: D016159:Tumor Suppressor Protein p53; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3