Objectives The evolution of the practice and recommendations regarding the axillary lymph node exploration in breast cancer patients tends toward promoting the sentinel lymph node as a gold standard in clinically N0 patients. This study aims to evaluate the accuracy and conformity of the extemporaneous pathological examination (EPE) with the definitive pathology examination (DPE) of the sentinel lymph node biopsy (SLNB) detected only with blue dye.

Methods We did a retrospective study including all the early-stage breast cancer patients (cT1/2N0) who underwent an axillary SLNB procedure with blue dye in our department of gynecology and obstetrics from 2008 to 2017. We did evaluate the performances of the EPE of the axillary sentinel lymph node by calculating the sensitivity, specificity, false positive, false negative, positive predictive value, negative predictive value, diagnostic efficacy, and the Youden index.

Results We have registered 441 procedures of EPE of axillary SLNB. When confronting the EPE response to the final response, we found that the sensitivity was 90.72%, the specificity 100%. There were no false-positive and 3.30% of false negatives. The positive predictive value was 100% and the negative predictive value 95.10%. The diagnostic efficacy of the EPE was 96.46% and the Youden index 0.91.

Conclusions The EPE is a good tool to evaluate blue dye-detected axillary sentinel lymph nodes during the surgery for early breast cancer.