Comparative features of comedo and noncomedo ductal carcinoma in situ of the breast on fine-needle aspiration biopsy.

To determine whether fine-needle aspiration biopsy (FNAB) can differentiate between comedo (C-DCIS) and noncomedo ductal carcinoma in situ (NC-DCIS), we reviewed retrospectively the preoperative FNAB and surgical biopsy slides of 13 cases of DCIS with adequate cytologic material. Eight were NC-DCIS and 5 were C-DCIS. Three (60 percent) of the C-DCIS and 7 (88%) of the NC-DCIS were nonpalpable lesions biopsied under conventional mammographic guidance. Three (60%) of the C-DCIS but only 2 (25%) of the NC-DCIS were considered either suspicious or positive for malignancy on FNAB, the remainder in both groups being atypical. A statistically significant difference in marked nuclear pleomorphism (60% of C-DCIS vs. 0% of NC-DCIS, P = 0.04) and large nucleoli (60% of C-DCIS vs. 0% of NC-DCIS, P = 0.04) was observed between these 2 groups. DCIS is morphologically diverse, and it appears that the cytologic features of individual cells on FNAB may distinguish C-DCIS from NC-DCIS.