Cytomorphologic features of classic and variant lobular carcinoma: A comparative study.

There are several subtypes of lobular carcinoma (LC), and their cytomorphologic features differ from classic lobular carcinoma (CLC). The finer details of the differences between CLC and variant lobular carcinoma (VLC) have not been adequately studied. A comparative study of 54 cases of CLC and VLC was done in order to verify any statistically significant differences between them. All cases had histologic confirmation of the diagnosis. Six parameters, which included cellularity, signet-ring cells, intracytoplasmic lumina (ICL), anisonucleosis, cell size, and prominent nucleoli, were studied. The only statistically significant findings were cellularity and cell size when compared to CLC. The cellularity in VLC was higher and the cells in VLC were larger when compared to CLC. There are no definite diagnostic features to identify VLC; however, in a cellular specimen with plenty of large cells with other features of LC, one should have a high index of suspicion of VLC. Diagn. Cytopathol. 22:370–375, 2000. © 2000 Wiley-Liss, Inc.