Reproducibility of mammographic classifications for nonpalpable suspect lesions with microcalcifications

Observer variability in interpretation of mammograms is a well-known problem, especially for microcalcifications. The classification of the mammographic findings depends upon this interpretation. We performed an intraobserver study to evaluate a breast imaging reporting and data system (BI-RADS) based method for description and classification of non-palpable lesions with microcalcifications. A set of 100 non-palpable mammographic lesions mainly consisting of microcalcifications was described and classified on two occasions, by two radiologists at an interval of 6 months. The intraobserver variability was evaluated with kappa statistics. The overall agreement for the classification was moderate (kappa 0.54). The lowest kappa values were observed for the categories "probably benign (BI-RADS 3., kappa 0.59)" and "suspicious abnormality (BI-RADS 4. kappa 0.44)". The clinical management (follow-up or biopsy) of non-palpable lesions consisting of microcalcifications depending upon radiological classification in the groups BI-RADS 3 (follow-up) and Bl-RADS 4 (biopsy) is therefore debatable.