Nipple-sparing mastectomy: lessons from ex vivo procedures.

Moderate size series have reported successful nipple-sparing mastectomy using a variety of surgical techniques. This study aimed to understand which aspects of these techniques are safe, necessary, and successful. Eight skin-sacrificing mastectomy specimens were used as ex vivo models of nipple-sparing mastectomy. After inking the resection margins of the specimen, the skin ellipse was elevated in the subcutaneous plane using a scalpel. The retroareolar breast tissue was taken as a margin specimen. The nipple was inverted and the nipple core removed. The hollowed-out nipple remnant (which would have remained with the patient in a true nipple-sparing mastectomy) was submitted for confirmatory histopathologic analysis. Precise identification of the duct margin directly beneath the nipple proved difficult once the duct bundle had been divided. Successful retroareolar margin identification was achieved by grasping the duct bundle with atraumatic forceps as soon as it became exposed. A cut made below and above the forceps resulted in a full cross-section of the duct bundle. Nipple core tissue was difficult to excise in one piece and cannot be oriented, thus complete evaluation of the specimen required examination of multiple levels. Histologic artifacts caused by freezing may be present in frozen sections of nipple core and retroareolar margin specimens; the impact of such changes must be considered when developing institutional protocols for this procedure. Evaluation of the hollowed-out nipple revealed that the inverted nipple must be substantially thinned to remove all ducts. Modification of technique resulted in more complete excision of duct tissue. This series of ex vivo procedures provides information that can be used to modify surgical and pathologic techniques for nipple-sparing mastectomy. When performing nipple-sparing mastectomy for breast cancer, these measures may be advisable as complements to careful patient selection.