Exfoliative cytology in the diagnosis of breast disease.

A total of 393 nipple discharge or scrape smears from 360 women were examined cytologically over a 12-year period. Twenty-nine breast cancers (8 per cent) have been histologically confirmed in this group, of which 16 had malignant smear cytology (sensitivity 55 per cent). Nine patients with breast cancer and positive cytology had impalpable tumours. Two of these cancers were not detected by any other investigation. Thirteen patients with nipple discharge had false-negative cytology, but there were no false-positive results (specificity 100 per cent). All patients with expressible or spontaneous nipple discharges and those with skin changes at the nipple should undergo examination of cytological smears.