Analysis of mammographic diagnostic errors in breast clinic.

Mammography is the gold standard for detection of early breast cancer and it is still the only diagnostic tool which shows reduction of the mortality from that. Despite that, there is a high chance of false negatives that can lead to diagnostic errors resulting in delays of treatment and worsening of prognosis. The aim of this study is to analyze the rate of false negative in mammography and assess the source of diagnostic errors. Two radiologists have retrospectively evaluated 500 mammograms performed between January 2008 and December 2011 in Breast Imaging Clinic. 250 patients (Group A) had been operated for breast cancer and 250 patients (Group B) were healthy woman submitted to mammography according to the guideline for early detection of breast cancer. In Group A, 138 patients (55.2 %) were true missed cancer, 61 had minimal sign (24.4 %) and 53 were false negative (FN) (20.4 %). The source of errors amongst the FN were in 42 % of cases due to perception, in 15 % to interpretation, in 10 % to subtle/unusual lesion characteristics, in 9 % error for satisfaction of search, in 7 % to inherent limitations of mammography, in 4 % to poor technique and 13 % for inadequate clinical management. The diagnostic errors in breast clinic services are not negligible. The largest number of FN results from perception errors, misinterpretation and inadequate clinical management. These can be related to factors such as inattention, fatigue or lack of experience. To reduce it, it is necessary to have a dedicated multidisciplinary staff and adequate equipment and workloads.