Caption |
Mammary gland: almost all interlobular and intralobular mammary ducts contain multiple and often coalescing small cauliflower-like projections. There is no evidence of fibrosis or inflammation around these ducts. 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 luminal cells contain lipid vacuoles.
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. |
