Caption |
Mammary gland: the neoplasm is composed, at its' periphery, of radiating frond-like structures resembling terminal end buds of the developing mammary gland separated by a small to moderate amount of moderately dense stroma. These frond like structures are cavitated and resemble ducts lined by a two cells-thick epithelium that show various degrees of dilation towards the center of the neoplasm. The presence of two discrete layers of epithelial cells in the ducts is suggestive of myoepithelial differentiation of the basal layer. Neoplastic cells are cuboidal to polygonal, with indistinct cell borders and a small amount of amphophilic cytoplasm. The nucleus is central, small, round to oval, and slightly hypochromatic. Mitoses are more numerous in the frond-like structures than in the areas of ductal differentiation. |