A Simple Intraductal Aspiration Method for Cytodiagnosis in Nipple Discharge

OBJECTIVE To increase cytodiagnostic accuracy for women with spontaneous nipple discharge using a simple intraductal aspiration method. STUDY DESIGN We compared the cytodiagnostic accuracy of the conventional squeezing collection method and intraductal aspiration by intravenous catheter in a total of 146 women with spontaneous nipple discharge in a single duct without a mass; they had been pathologically identified at Kaohsiung Medical University Hospital. RESULTS Adequate specimens were collected in 96.6% (141/146 cases) of the sample by the intraductal aspiration method as compared to 76.0% collected by the conventional squeezing method (P < .05). An adequate specimen should consist, at a minimum, of six cohesive clusters of well-preserved epithelial cells, with each cluster composed of at least five cells other than foam cells. The cytologic diagnosis was divided into five categories: positive in 9 cases, suspicious in 10, negative with atypical findings in 59, negative in 33 and inadequate specimens in 35 cases that employed the squeezing method. These results were less satisfactory than with the intraductal aspiration method: the smears were positive in 17 cases, suspicious in 14, negative with atypical findings in 78, negative in 32 and inadequate specimens in 5. Our results showed a sensitivity of 92.3% and specificity of 93.9% for the intraductal aspiration method as compared to a sensitivity of 52.9% and specificity of 89.3% for the squeezing method. Among the 27 cancers in this series, correct cytodiagnosis, including suspicious cases, was made in 24 cases by intraductal aspiration, with an accuracy of 88.9%, as compared to the 33.3% (9/27) accuracy of the squeezing method (P < 0.5). CONCLUSION For patients with spontaneous nipple discharge, the intraductal aspiration method provides much more accurate cytodiagnosis than does the conventional squeezing method.