Abstract
Objectives: This study aimed to disclose the importance of nipple discharge (ND) and the accuracy of its economic and fast cytological interpretation.
Methods: All ND cytology cases for Saudi patients done between 2004 and 2013 were retrieved from the Pathology e-system. Only cases that have subsequent tissue diagnoses were included in this study (n = 228). Age and bloody nature of the ND were both tested for association with a higher chance of carcinoma. Diagnostic accuracy of ND cytology was calculated twice, including and excluding the "atypical" cases.
Results: Specificity and positive predictive value were 100% for ND cytology in both cases. Sensitivity (34.6%; 52.9%), negative predictive value (93.15 %; 96.1%), false-negative rate (65.4%; 47.1%), accuracy rate (93.4%; 96.2%), when atypical cases were included and excluded; respectively. Only 10.5% of the patients complaining from nipple discharge had breast cancer. For those who had cancer, nipple discharge cytology was positive and showed the cancer cells in only 37.5%, while the rest were false negative. Bloody ND disclosed a significant association with malignancy (p < 0.001), but the association was statistically not significant for old age (p = 0.062).
Conclusions: The prospect of having breast cancer with the presentation of ND is low, and it can be missed by studying the ND cytology alone in a high proportion of cases. Excluding the atypical category did not make a significant improvement in the test's accuracy.