Breast duct microendoscopy in nipple discharge: microbrush improves cytology.

Background: Breast duct microendoscopy is a new technique that allows direct visualization of the mammary ductal epithelia and has the potential to provide greater accuracy in the diagnosis of benign and malignant breast conditions. We have already established the feasibility of BDME on mastectomy specimens and in patients both under general and local anesthesia. It was the aim of this study to investigate the use of BDME in patients with pathological nipple discharge and to explore the feasibility of using an endoluminal microbrush to take cytology samples from specific lesions.

Materials And Methods: Breast duct microendoscopy was offered to all patients undergoing surgery for nipple discharge. Surgery included microdochectomy (younger women) and total duct excision (especially in postmenopausal women). The microbrush was used to collect samples whenever an endoluminal papilloma was seen on endoscopy. The results of microbrush cytology samples were compared to ductal lavage samples.

Results: Fifty consecutive patients undergoing microdochectomy or total duct excision for nipple discharge had breast microendoscopy (28 general, and 22 under local anesthesia). Thirty-one patients had microdochectomy and nineteen had total duct excision. Visualiza- tion of discharging ducts was accomplished in 100% cases. Endoluminal abnormalities were seen in 33 (66%) patients and dilated ducts were seen in 17 patients. Among the 33 patients, 15 had single papilloma, 3 multiple papilloma and 15 inflammation (erythema, fronds, adhesions). Seven out of eight patients with an intraductal papillorna who had microbrush cytology showed papillary cells whereas only 2 out of 11 patients who had ductal lavage were positive for papillary cells. Thus the sensitivity of the brush cytology technique for the diagnosis of papilloma was 87.5% and the sensitivity of ductal lavage 18% (p = 0.0055).

Conclusion: Breast duct microendoscopy is an effective way of establishing the etiology of nipple discharge. The microbrush increases the sensitivity of cytology significantly.