Cytodiagnosis of nipple discharge: a study of 602 samples from 484 cases

To find out the gross and microscopic differentiating features between nipple discharges (ND) due to various breast lesions, smears of 602 ND samples from 484 cases were reviewed by one of the investigators (D.K.D.). The reviewed cytodiagnoses were as follows: benign nipple discharge (59.1%), inflammatory ND (6.5%), ?papillary lesions (2.5%), papillary lesions (20.6%), papillary lesions with atypia (3.8%), duct cells with atypia (0.2%), suspicious for malignancy (0.5%), malignant ND (1.2%), and inadequate (5.6%). Following review, samples with epithelial abnormalities (?papillary lesion, papillary lesion with and without atypia, duct cells with atypia, suspicious for malignancy, and malignancy) increased from 16.6% to 30.4% of adequate samples (P < 0.0001). 37.9% unilateral ND samples showed epithelial abnormalities, as opposed to 18.9% of bilateral ND samples (P < 0.0001). Bloodstained ND showed epithelial abnormalities in 41.5% samples, as compared to 22.1% of ND with other specified gross characteristics (P