Although many modalities have been established to diagnose breast cancers, it is sometimes difficult to reveal nonpalpable cases.Duct lavage cytology was originally established to reveal groups at high risk for breast cancers by detecting metaplastic ductal cells. We report here a case where duct lavage was useful for revealing a small cancer that had been undetected by repeated bloody nipple discharge and cytological examinations. Duct lavage cytology may be of use in cases where nipple discharge of unknown origin persists.
