ADENOMYOEPITHELIOMA OF THE BREAST - FINE-NEEDLE SAMPLING WITH HISTOLOGIC, IMMUNOHISTOLOGIC, AND ELECTRON-MICROSCOPIC ANALYSIS

Fine-needle sampling was performed in a woman with a subareolar breast mass. The cytologic diagnosis was consistent with a benign sweat glan d-type tumor. Cytologic features included epithelial cells and spindle -shaped cells lying free or in fibrillary myxoid ground substance. His tologic study revealed the biphasic appearance of this tumor composed of proliferating myoepithelial cells and glandular epithelial cells as supported by immunohistologic and electron microscopic analyses. Epit helial cells were strongly positive for cytokeratins, and spindle cell s were positive for actin, S-100 protein, and keratin and showed ultra structurally typical features of myoepithelial cells.