Caption |
Mammary gland: an interlobular mammary duct contains multiple coalescing small cauliflower-like projections. These projections are composed of a slender papillary core covered by several layers of small spindloid cells with indistinct cell borders, a scant amount of acidophilic cytoplasm, and a small oval hyperchromatic nucleus. Covering these spindloid cells is a one cell-thick layer of cuboidal to low columnar luminal cells with ill-defined cell borders, a moderate amount of acidophilic cytoplasm, and a medium-size central hypochromatic nucleus. Anisokaryosis and anisocytosis are mild. Mitoses are not detected. A few cells with a luminal phenotype contain lipid vacuoles (arrowheads).
The presence of two layers of cells indicates that the cell that gave rise to these lesions is not committed to the luminal or to the basal lineage, and hence these lesions may be categorized as "complex" lesions. |