Pathologic Assessment of Surgical Margins on Frozen and Permanent Sections in Breast Conserving Surgery

The diagnostic value of frozen section was evaluated in the histologic assessment of surgical margins obtained by wide excision of breast tumors. There were 87 patients with unilateral breast cancer, and 5 with bilateral breast cancers. The periphery of the excised breast tissue was peeled like an orange and histologically examined by frozen and permanent section. If either in situ or infiltrating microscopic tumor was found at the margin, it was considered positive. Using frozen sections, the margin was judged histologically positive or suspicious in 30 tumors (31%) and negative in 67(69%) tumors. Positive surgical margins were histologically confirmed by permanent section in 20(67%) of the 30 tumors diagnosed as positive or suspicious on frozen section. Another 10 tumors had negative margins. In 4 tumors, however, while the initial or re-excised margin was negative on frozen section, the margins were positive by permanent section. These surgical margins were positive due exclusively to the presence of ductal carcinoma in situ (DCIS). Evaluation of surgical margins in breast cancer by frozen section, thus exhibited a diagnostic accuracy of 86&prtcnt;, a sensitivity of 83%, and a specificity of 86%. It is concluded that frozen sections are useful in the determination of involvement of surgical margins after the wide excision of breast cancer. It must be pointed out that frozen sections will ofter overestimate involvement of the surgical margins.