Fine needle aspiration cytology of the breast: improving the predictive value of equivocal cytologic reports by monoclonal antibody B72.3

The monoclonal antibody B72.3 was tested on 77 consecutive patients with masses where cytology was reported as equivocal; all patients had been examined by palpation, sonography and mammography and underwent surgical biopsy. The positive predictive value of an equivocal cytologic report in this series was 49.3% (38 carcinomas, 39 benign lesions). B72.3 immunocytochemical assay was highly accurate (sensitivity = 94.7%, specificity = 82.0%) and had a higher positive predictive value (83.7%) than conventional cytology. The B72.3 assay may be valuable in cases with equivocal cytology, as it may improve the final diagnostic judgement.