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

To find out the gross and microscopic differentiating features between nipp le 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 revi ewed cytodiagnoses were as follows: benign nipple discharge (59.1%), inflam matory ND (6.5%). ?papillary lesions (2.5%), papillary lesions (20.6%), pap illary lesions with atypia (3.8%), duct cells with atypia (0.5%), suspiciou s for malignancy (0.5%), malignant ND (1.2%), and inadequate (5.6%). Follow ing review, samples with epithelial abnormalities (?papillary lesions, papi llary lesions with and without atypia, duct cells with atypia, suspicious f or malignancy, and malignancy) increased from 16.6% to 30.4% of adequate sa mples (P < 0.0001). 37.9% unilateral ND samples showed epithelial abnormali ties, as opposed to 18.9% of bilateral ND samples (P < 0.0001). Bloodstaine d ND showed epithelial abnormalities in 41.5% samples, as compared to 22.1% of ND with other specified gross characteristics (P <0.0001). The samples with epithelial abnormalities differed significantly from benign and inflam matory ND in respect of frequency of benign duct cells, duct cells with aty pia, papillary clusters or with or without atypia, malignant cells, columna r cells, red blood cells, inflammatory cells, and background lipid vacuoles (P < 0 0.01 to < 0.0001). The ND samples with suspicious and malignant cyt ology, besides the presence of malignant cells (P < 0.0001), differed signi ficantly from rest of the lesions in respect of foam cells (P < 0.0001), re d blood cells (P <0.01), and inflammatory cells (P < 0.05). When compared w ith histopathological diagnosis in 20 cases, the benign or malignant nature of the lesion was correctly identified in ND in 80% cases. The ND cytologi es in 7 histologically proved malignant cases were malignancy (3 cases), su spicious for malignancy (1 case), papillary lesion with atypia (1 case), pa pillary lesion (1 case), and benign ND (1 case). (C) 2001 Wiley-Liss, Inc.