Significance of nipple discharge clinical patterns in the selection of cases for cytologic examination.

The cytodiagnostic significance of the clinical patterns (types and sites) of nipple discharges was studied in 5,305 cytologically examined discharges from 3,687 women in a consecutive series of 50,181 self-referred women in whom 1,062 breast cancers were detected. The clinical patterns were correlated with cytologic and histologic results in both the whole series and in 119 biopsied cases, and the relative risk of association with breast cancer was calculated for each pattern. As a whole, aside from the pattern, cases with nipple discharges showed a higher relative risk (48.5) than did asymptomatic cases, but a bloody nipple discharge was by far more frequently associated with cancer than was any other pattern, being present in 70% of the cancer cases and in almost all cancer cases with suspicious cytologic findings in the discharge smear. The presence of a nipple discharge, being associated with a higher risk of breast cancer, is an indication for a careful physical examination; systematic cytologic examination should be limited only to bloody discharges. Since cancer is rare in cases with nonbloody discharges and is difficult to detect in cytologic smears of such discharges, systematic cytologic examination of all nipple discharges would not be cost-effective.