breast duct endoscopy breast duct endoscopy breast duct endoscopy is a method used to examine the lining of the lactiferous ducts to look for abnormal tissue. a very thin, flexible, lighted tube attached to a camera is inserted through the nipple, and threaded into the breast ducts deep in the breast. tissue and fluid samples may be removed during the procedure. breast duct endoscopypurposeexamine the lining of the lactiferous ducts t