Occult Involvement of Nipple by Malignancy Occurs in 14% of Therapeutic Nipple-Sparing Mastectomies
Rachel E Kaplan, Syed A Hoda. New York Presbyterian Hospital/Weill Cornell Medical College, New York, NY
Background: Nipple-Sparing Mastectomy (NSM) is an increasingly utilized surgical option in managing breast carcinoma (ca); however, data on malignant involvement of nipple margin, a finding of obvious surgical and clinical significance, are scant.
Design: Consecutive NSM specimens, including those performed for therapeutic (Th-NSM) and prophylactic (Pr-NSM) purposes, over a 4-year period (2007-to date), were studied. A separately submitted retro-areolar cross-sectional “true” nipple margin (NM) was evaluated via frozen section examination (FSE) whenever requested, and by permanent H&E-stained preparations.
Results: 325 consecutive NSM specimens, including 208 (64%) Th-NSM and 117 (36%) Pr-NSM, were studied. All nipples were clinically unremarkable. 86% (179/208) of NM from Th-NSM, and 100% (117/117) of NM from Pr-NSM showed no histopathological abnormality. 14% (29/208) of NM in Th-NSM and 0% (0/117) of NM in Pr-NSM showed malignancy. NM in Th-NSM showed ductal ca in situ (DCIS) in 16/208 (8%) cases, lobular ca in situ (LCIS) in 5/208 (2%), invasive ductal ca in 4/208 (2%), invasive lobular ca (Figure 1) in 4/208 (2%). FSE was requested in 187 of 325 TNM (58%) with a sensitivity of 64% and specificity of 99% (false-negative: 9, false-positive: 1). Tumor size, grade, estrogen receptor status, HER2 status, lymphovascular involvement, and lymph node involvement were not associated with malignancy in NM (p > 0.05). Complete nipple resection (CNR), status-post NSM, was performed in 69% (20/29) of positive NM cases. 5 cases with LCIS in NM, status-post NSM, did not have CNR. Residual malignancy in CNR was found in 55% (11/20, including 3 cases of invasive ca).
Conclusions: In this series, 14% (29/208) of nipples from Th-NSM specimens showed occult malignancy, and the most common malignancy in nipple margin was DCIS (8%). No nipple from Pr-NSM (0/117) showed malignancy. FSE of nipple (a test with high specificity and low sensitivity) is important, since no routine pathological parameter is predictive of nipple margin involvement.
Figure 1: Frozen section of nipple margin with invasive lobular carcinoma.
Monday, March 19, 2012 9:15 AM
Platform Session: Section B, Monday Morning