Ductoscopy uses a microendoscope for direct visualization of the ductal system of the breast and aspiration of lavage fluid to be used in cytological analysis. [1, 2, 3] Ductoscopy allows a targeted approach to the diagnosis of intraductal breast disease. [4, 5, 6, 7, 8, 9] Ductoscopy can serve as an adjunct to established techniques of breast imaging but is not a substitute. [10, 11, 12, 13]
Many benign and malignant breast diseases originate from ductal cells. Ductoscopy can be performed for diagnostic or therapeutic purposes to assist in the detection and treatment of these conditions. [4, 5, 6, 7, 8, 9]
There are no specific absolute contraindications to the procedure.
Equipment for ductoscopy includes the following:
Bowman lacrimal probe
The procedure is performed under local anesthetic and sedation. The local anesthetic is applied in cream form on the nipple. To minimize the pain for most patients undergoing mammary ductoscopy, Wang et al recommend the duration of the procedure should not exceed 12 minutes.  They also recommend local anesthesia in patients with retracted nipples. 
The patient is placed in supine position with the arm preferably extended on a side board.
First, cleanse the nipple-areola complex and exfoliate to remove any keratin plugs.
Massage the breast towards the nipple and identify the fluid-producing ducts.
Attach a sterile ductoscope to a draped camera cord and sterile light cord.
A sterile disposable cannula is inserted over the scope after priming the catheter with either lidocaine or saline. Air bubbles should be removed carefully from the cannula.
Focus the scope and white balance the camera. Identify the duct.
Dilate serially using lacrimal dilators.
Introduce the endoscope sheath and the endoscope through it.
Compress the nipple against the scope with thumb and forefinger.
Distend the duct with a mixture of normal saline and local anesthetic.
Advance the endoscope.