Micropapillary Carcinoma of Breast
Micropapillary Carcinoma of Breast: The tumor cells are arranged in micropapillary, tubulo-alveolar, or morular clusters that are surrounded by lacunae or clear spaces. The micropapillary fronds lack fibrovascular cores. The lacunae may create an impression of lympho-vascular invasion. True lympho-vascular invasion is indeed quite commonly present.
The tumor cells have moderate quantity of eosinophilic cytoplasm and high-grade nuclei with frequent mitoses. The cells in micropapillary clusters have reverse polarity with the apical surface polarized to the outside and in contact with the stroma. The stroma is usually desmoplastic. DCIS of micropapillary and cribriform types is usually present. Microcalcifications are commonly seen.