RETROSPECTIVE C-ERBB-2 IMMUNOSTAINING IN ASPIRATION CYTOLOGY OF BREAST-CANCER

Fifty fine-needle aspiration cytologies of breast that were diagnosed as carcinomas were retrieved from the files and retrospectively evalua ted for the expression of c-erbB-2 oncoprotein using standard immunocy tochemical methods. Corresponding histologic sections of all tumors we re similarly studied. Seventeen fine-needle aspirates (34%) reacted po sitively for the presence of c-erbB-2 oncoprotein. All but one (32%) o f the corresponding tissue sections were also positive for c-erbB-2 by immunohistochemistry. All positive cases were infiltrative ductal car cinomas with a preponderance of the comedo type. Positive reactions we re localized in the cytoplasmic membrane of rumor cells. The staining was either present in all cells throughout a tumor, or it was complete ly absent. We conclude that immunocytochemistry for c-erbB-2 oncoprote in can be performed on fine-needle aspiration cytology samples that ar e previously fixed and stained with the Papanicolaou technique. Furthe rmore, the sensitivity of immunostaining results are comparable to tha t obtained in histologic sections. (C) 1994 Wiley-Liss, Inc.