title: Malignant transformation of adenomyoepithelioma of the breast by a monophasic population: a report of two cases and review of literature.
abstract: Two cases of adenomyoepithelioma of the breast with malignant transformation by monophasic population of cells are presented. The underlying benign adenomyoepithelioma with typical biphasic architectural pattern was identified and represented at least 30% of the tumor in each case. In both cases, malignant portion of tumor was composed of relatively uniform monophasic population of highly atypical cells. The malignant component in case 1 was positive for pan cytokeratin, myoepithelial markers, and basal-type cytokeratins and also focally positive for luminal-type of cytokeratins, but negative for hormone receptors (estrogen and progesterone) and HER-2/neu protein overexpression. The malignant component in case 2 was positive for spectrum of myoepithelial markers but negative for luminal cytokeratins, hormone receptors and HER-2/neu protein overexpression. The bilinear immunophenotype in the case 1 suggests that the malignant tumor may have developed from precursor multipotent cells that can differentiate into both luminal epithelial and myoepithelial cells, although malignant component in case 2 appears to be the of pure myoepithelial phenotype.
authors.affiliation: Department of Pathology, University of Medicine, Targu Mures, Romania.
authors.forename: Cristina
authors.initials: C
authors.lastname: Marian
authors.forename: Adela
authors.initials: A
authors.lastname: Boila
authors.forename: Daniela
authors.initials: D
authors.lastname: Soanca
authors.forename: Minerva
authors.initials: M
authors.lastname: Malau
authors.forename: Daniela Maria
authors.initials: DM
authors.lastname: Podeanu
authors.forename: Erika
authors.initials: E
authors.lastname: Resetkova
authors.forename: Simona
authors.initials: S
authors.lastname: Stolnicu
mesh_terms: D055331:Adenomyoepithelioma / Q000737:chemistry / Q000473:pathology*; D000328:Adult; D001943:Breast Neoplasms / Q000737:chemistry / Q000473:pathology*; D002471:Cell Transformation, Neoplastic; D005260:Female; D006801:Humans; D007633:Keratins / Q000032:analysis; D008875:Middle Aged
chemical_list: D007633:Keratins