Sampling of grossly benign breast reexcisions: a multidisciplinary approach to assessing adequacy.

The widespread use of breast-conserving therapy in the treatment of early-stage breast cancer has resulted in increasing numbers of reexcision specimens requiring histologic assessment for residual disease and margin status. Because many reexcisions are performed for only microscopically positive or close margins, reexcision specimens often appear grossly negative and directed tissue sampling cannot be performed. The issue of adequate sampling in these specimens has not been addressed in the literature. A multidisciplinary approach to identifying the clinically important lesions in breast reexcisions and a cost-effective approach to tissue sampling are needed. We reviewed 97 consecutive cases of grossly negative breast reexcisions in which all tissue had been embedded. Forty-seven specimens contained residual invasive or in situ carcinoma and 50 were histologically negative. Detailed histologic findings were presented to a medical oncologist, a radiation oncologist, and a surgeon, who assessed the clinical impact of each diagnosis. Of the 47 positive specimens, 30 resulted in a major change in patient management (recommendation for additional surgery), 10 resulted in minor changes (alteration in radiation dose or adjuvant chemotherapy regimen), and 7 did not alter management. A total of 1867 blocks were submitted. If one block per centimeter of maximal tissue dimension had been submitted and the remainder of the specimen examined only if initial sections revealed invasive or in situ carcinoma, then 901 blocks would have been processed (52% reduction), but we would have missed an average of 3.7 cases resulting in a major change in therapy, and 3.3 cases resulting in a minor change. In contrast, two blocks per centimeter would have missed an average of less than one case each of diagnoses resulting in major and minor therapy changes (0.9 and 0.8 cases, respectively), and 315 (17%) fewer tissue blocks would have been processed. We recommend submitting two blocks per centimeter in grossly benign reexcisions, and examining the remainder of the tissue only if carcinoma is detected on initial sections.