Duct endoscopy and endoscopic biopsy in the evaluation of nipple discharge.

Microdochectomy is usually performed on patients with nipple discharge caused by intraductal proliferative lesions, such as intraductal papilloma and carcinoma. But this operation often sacrifices large amounts of normal mammary gland even when the lesion is a benign intraductal papilloma a few millimeters in diameter. We have developed duct endoscopy for the mammary duct system, and have reliably performed biopsies for intraductal proliferative lesions intraductally. From June 1989 to April 1990, we examined 22 cases by duct endoscopy, and performed endoscopic biopsy in 16 cases. The method of endoscopic biopsy is as follows. First, a bougie is inserted, without anesthesia other than Xylocaine jelly, into the orifice of the duct to enlarge it. Second, the outer cylinder and the inner needle are inserted; then the inner needle is removed, and the endoscope is inserted. After examination, the outer cylinder is moved up to the lesion to be biopsied and the endoscope is taken out. Then a sample is taken into the outer cylinder by aspiration. We diagnosed 10 cases of benign lesion and 5 cases of malignant lesion by cytological and/or histological examination. In conclusion, endoscopic biopsy, aided by duct endoscopy, is a useful and harmless diagnostic procedure in the evaluation of nipple discharge.