R3 breast lesions - are we categorising and managing them correctly?

The Royal College of Radiologists Breast Group has recently brought out a breast imaging classification system to ensure clear communication regarding the likelihood of malignancy within breast lesions and the need for further investigation to establish a definite diagnosis. The R3 category is used for indeterminate/probably benign findings, where there is a small risk of malignancy and further investigation in the form of further imaging and usually biopsy is required. Our aim was to audit symptomatic imaging in a large teaching hospital to ensure: lesions classified as R3 were appropriately managed; and lesions diagnosed as malignant on histopathology were not inappropriately categorised as R3 on imaging.

A retrospective 6-month audit was carried out reviewing all cases coded as R3. Further investigation and outcome of these lesions was then assessed using radiology, pathology and multi-disciplinary meeting records. All cases that proved to be malignant on histology had their imaging reviewed by three independent radiologists to see if they had been correctly coded as R3.

This study included 140 lesions. Of these, 28 (20%) were downgraded to benign on further imaging and 111 (79%) were biopsied. One patient refused biopsy. Nineteen (14%) lesions were malignant. On imaging review of malignant cases, the consensus was R3 in all.

Review of our practice shows that we are adequately managing R3 breast lesions in 100% of cases. It is important that all R3 lesions are biopsied as a significant proportion will be malignant. In our study 14% were malignant.