FINE-NEEDLE SAMPLING OF A CASE OF CARCINOMA OF THE BREAST WITH NEUROENDOCRINE DIFFERENTIATION

Fine-needle sampling was performed in a woman with a left breast lump. The cytologic diagnosis was consistent with a poorly-differentiated c arcinoma. Cytologic features included medium-to-large, round, and spin dle-shaped cells with scanty cytoplasm, nuclear molding, and rosette-l ike structures. Histology revealed an endocrine pattern. Immunohistoch emical staining was positive for epithelial and neuroendocrine markers , and electron microscopy showed many small membrane-bound electron-de nse granules, confirming the diagnosis of breast carcinoma with neuroe ndocrine differentiation. DNA flow cytometry and cytogenetic analyses revealed a near-tetraploid tumor. (C) 1996 Wiley-Liss, Inc.