[151] Utility and Accuracy of Frozen Sections in Nipple Sparing Mastectomies

RS Bains, WG Watkin. NorthShore University HealthSystem, Evanston, IL

Background: Nipple sparing mastectomies NSM are being performed with greater frequency in patients undergoing prophylactic and therapeutic mastectomies because of superior cosmesis. In some institutions, a subareolar margin SAM is submitted for frozen section (FS); if cancer is identified, the nipple-areolar complex (NAC) is removed in the same procedure. Existing literature on the technique has focused primarily on patient selection criteria and prospective outcomes; however, there have been no comprehensive studies examining the utility and accuracy of FS in the management of these patients. Herein we report our experience with evaluating SAM by frozen section in NSM.
Design: We reviewed all NSMs performed at our institution from 12/2007 to 8/2009. Indications for surgery were tabulated. FS diagnosis was compared to findings on permanent section of the subareolar margin. Clinical and pathological characteristics (tumor type, size and multifocality) of patients with positive and negative subareolar margins were compared.
Results: 104 NSMs from 54 patients were evaluated. FS evaluation was performed in 74 prophylactic NSMs from 38 patients with a family history of breast cancer or known BRCA mutation. 30 NSMs (18 therapeutic / 12 prophylactic) were performed on 16 patients with current or previous history of breast cancer. Frozen and permanent sections showed 100% concordance in all cases. Frozen and permanent sections of the SAM were positive in 5 of 18 therapeutic mastectomies and in 0 of 86 prophylactic mastectomies. 4 of 5 NSMs with positive SAM had multifocal disease whereas 2 of 13 NSMs with negative SAM had multifocal disease. ILC was present in 3 of 5 positive SAM. Tumor size was not statistically significant. The pathological characteristics of therapeutic NSM groups are shown in TABLE 1.

Table 1
Positive SAMNegative SAM
Mixed IDC/ILC2

Conclusions: FS evaluation of the SAM can be performed accurately. FS evaluation of the SAM in prophylactic mastectomies may be unnecessary. Patients with known disease are at a higher risk of NAC involvement (fisher exact test, p < 0.001). Of the parameters evaluated, multifocality and ILC had a higher rate of positive SAM (p = 0.02 and p = 0.01, respectively). Patients undergoing therapeutic NSM, especially with multifocal disease, should be considered for frozen evaluation of the SAM to avoid a second procedure.
Category: Breast

Monday, March 22, 2010 1:00 PM

Poster Session II # 31, Monday Afternoon


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