Confocal Laser Microscopy for Intraoperative Margin Assessment in Breast-Conserving Surgery: A New Procedure in the Pathology Laboratory Workflow.

One of the breast-conserving surgery goals is to achieve negative resection margins and avoid reoperation. Therefore, accurate intraoperative margin assessment is essential, but still challenging. Recently, confocal microscopy devices, such as Histolog Scanner (HS), have shown promise for intraoperative margin assessment. The aim of this study was to assess HS for the intraoperative examination of lumpectomy specimens by the pathologists of our institute. Intraoperative margin assessment was performed by macroscopic assessment and by HS imaging to provide information for re-excision decision-making. The specific contribution of HS was evaluated by comparing the HS-based findings with the final pathology reports based on formalin-fixed paraffin-embedded tissue analysis. The study population included 20 women with histologically confirmed invasive breast carcinoma who underwent breast-conserving surgery (mean age of 62.9 y; 41 to 88 y; 21 tumors in total). HS led to the same decision as macroscopic examination in 76.2% of cases and prompted additional re-excisions in 19% of cases. Compared with the pathology reports, the accuracy rates of the macroscopic and HS assessments were 81% (58.1 to 94.6) and 95.2% (76.2 to 99.9), respectively. Moreover, 5 cases are described to illustrate HS practical contribution and limitations. In conclusion, HS is user-friendly, generally reliable, and enhances the routine macroscopic examination by providing detailed imaging of lumpectomy specimens. In combination with macroscopic examination, HS is an effective tool for intraoperative margin assessment, assisting both pathologists and surgeons in making accurate intraoperative decisions regarding margin re-excision, thereby preventing the need for new surgical operations.