Microscopic Description -- Mass in the Left Breast


The incisional biopsy showed a biphasic infiltrative tumor with multifocal areas of necrosis (Figs. 5, 6, 7, 8, 9, 10, 11) The epithelial component had solid and papillary architecture with marked nuclear pleomorphism and brisk mitotic activity 15 mitoses per 10 HPF. The in situ component was not seen. The intraluminal secretion was PAS positive, with and without diastase, but not for mucicarmine. The stromal component also demonstrated marked pleomorphism and brisk mitotic activity (15 mitoses per 10 HPF). Immunohistochemical examination showed EMA (Dako) and cytokeratin AE1/AE3 (Fig. 12) (Boehringer Mannheim) positvity in the epithelial component, but not in the spindle cell component and vimentin positivity (Fig. 13) in both the epithelial and spindle cell component. Spindle cell component was also negative for smooth muscle actin (Sigma), S-100 (Dako) and myosin. Morphology of this tumor was different from that of lumpectomy specimen removed three years earlier. The tumor did not express estrogen or progesterone receptor and Her-2/neu on immunohistochemical examination. Subsequent mastectomy specimen showed 6.5 cm tumor with identical morphology and lymphovascular invasion.


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