EP032/#969 Evaluation of the reliability of the extemporaneous pathological examination for the pathological diagnosis of breast tumors

Objectives

We aim to compare the performance of the extemporaneous pathological examination (EPE) to the definitive pathology examination (DPE) for the pathological diagnosis of the nature of breast tumors.

Methods

It is a retrospective single-center study including all the patients who an EPE to determine the pathological diagnosis of the nature of a breast tumor in our institution from 2007 to 2017. The uninterpretable samples because totally necrotic, crushed, electro-coagulated, and/or poorly preserved were excluded. We did evaluate the performances of the EPE of the surgical margins by calculating the sensitivity, specificity, false-positive (FP), false negative (FN), positive predictive value (PPV), negative predictive value (NPV), diagnostic efficacy, and the Youden index.

Results

The EPE was performed 812 times on a breast surgical specimen for pathological diagnostic purposes. Extemporaneous responses were ‘benign’ for 415 cases (51.10%), ‘malignant’ for 332 cases (40.88%), and ‘delayed’ for 65 cases (8%). The DPE objectified 457 benign lesions (56.3%) and 355 malignant lesions (43.7%). The response of the EPE was concordant with that of the DPE in 737 cases (406 true negatives +331 true positives). There is a single case of FP and 9 FN. Regardless of the delayed answers, the EPE for the pathological diagnosis of the nature of breast tumors has a sensitivity of 97.35% and a specificity of 99.75%. Its PPV and NPV were 99.69% and 97.83% respectively. Its diagnosis efficiency was 98.52% and the Youden index was 0.97.

Conclusions

The EPE for histological diagnostic purposes in the management of breast tumors remains an excellent diagnostic test when no preoperative diagnostic tools are available