FINE-NEEDLE ASPIRATION CYTOLOGY OF PLEOMORPHIC LOBULAR CARCINOMA OF THE BREAST - COMPARISON WITH THE CLASSIC TYPE

BACKGROUND. The pleomorphic variant of invasive lobular carcinoma shar es the typical infiltrating histologic pattern of classic invasive lob ular carcinoma, but differs from it in its nuclear pleomorphism and ag gressive behavior. The purpose of this study was to describe the fine- needle aspiration (FNA) cytologic findings of the pleomorphic variant of lobular carcinoma and to compare them with those of classic lobular carcinoma. METHODS. Among 405 breast FNA performed in 1995, 7 example s of classic infiltrating lobular carcinoma and 4 cases of this neopla sm's pleomorphic variant were identified; all were histologically conf irmed. The FNA from three of the four pleomorphic variant cases and fr om two of the seven classic lobular carcinoma cases were diagnostic of malignancy; these were evaluated for a variety of cytologic criteria, which were graded from 0 to 3. RESULTS. Although exhibiting many cyto logic features in common with the classic type, such as indian files a nd cytoplasmic vacuoles, the FNA of the pleomorphic variant differed i n their tendency to yield greater cellularity, larger cell size, and, particularly more pleomorphic nuclei. CONCLUSIONS. The FNA cytologic f indings of the pleomorphic variant of lobular carcinoma are characteri stically hybrid between those of classic lobular carcinoma and ductal carcinoma. (C) 1997 American Cancer Society.