Figure 1.

a-c: Three-tiered nuclear grading system showing grade 1(1a), grade 2 (1b) and grade 3 (1c) cytologic features. d: Solid pattern ductal carcinoma in-situ with grade 2/3 atypia and microcalcification (upper left field), and solid pattern ductal carcinoma in-situ with central necrosis and nuclear grade 2/3 (lower right field). e: Solid pattern ductal carcinoma in-situ with grade 3/3 atypia and central necrosis (comedo-pattern ductal carcinoma in-situ). f: Cribriform pattern ductal carcinoma in-situ with grade 2/3 atypia and foci of necrosis.