[94] Intraoperative Evaluation of the Nipple Margin in the Decision Making for Nipple Sparing Mastectomies

Andrea L Barbieri, Veerle Bossuyt. Yale-New Haven Hospital, New Haven, CT

Background: Nipple-sparing mastectomies (NSMs) are increasingly performed for the surgical treatment of invasive and in situ breast cancer. Evaluation of the nipple margin by frozen section is used to decide at the time of surgery whether or not to preserve the nipple. We examined the effectiveness of this approach.
Design: We studied a consecutive series of NSMs at our institution (6-2010 to 5-2011). Discrepancies between frozen section and final permanent diagnoses were recorded. We retrospectively reviewed both frozen section and permanent slides of all cases.
Results: Sixty five nipple-sparing mastectomies were sent to Pathology in one year, Fifty five (85%) with seperate designated "nipple-core" margins. Of these 55 nipple margins, 41 (75%) were sent for intraoperative evaluation.

Table 1: Nipple Margin Specimens
Number of CasesFrozen Section DiagnosisPermanent DiagnosisNipple Preserved?
31Benign breast tissueConfirmedY (Yes)
4Intraductal hyperplasiaConfirmedY
1Minimal epithelial proliferation with atypiaDiscrepant, Benign breast tissueY
1Extensive involvement by invasive lobular carcinomaConfirmedN (No)
1Papillary lesion, no evidence of carcinomaConfirmedY
1Focal intraductal proliferation suspicious for atypiaDiscrepant, Benign breast tissueN
1IDP with intraductal hyperplasiaConfirmedY
1Cannot rule-out low grade DINConfirmedY
DIN=ductal intraepithelial neoplasia, IDP=intraductal papilloma

Review of frozen section and permanent diagnoses revealed two discrepancies: a diagnosis of "minimal epithelial proliferation with atypia" and "ductal proliferation suspicious for atypia" were not confirmed on permanent sections. One of these cases resulted in surgical excision of the nipple. Subsequent evaluation of the nipple revealed no abnormalities. In thirty nine cases the intent to preserve the nipple was maintained; in two cases the decision was changed. The diagnosis triggering this decision could not be confirmed on review of permanent sections in one of these two cases. Retrospective review of the slides revealed tangential sectioning and sloughing of epithelial cells as common potential pitfalls.
Conclusions: Findings necessitating surgical excision of the nipple are infrequent at the nipple margin. Our data suggests that there is a significant risk of overinterpreting findings at the nipple margin as atypical leading to inappropriate excision of the nipple. In our series no false negative frozen section diagnoses were recorded.
Category: Breast

Wednesday, March 21, 2012 1:00 PM

Poster Session VI # 1, Wednesday Afternoon

 

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