Sarah Susan Freel Nielsen DO, Presenter: Nothing to Disclose

Robyn Leah Birdwell MD, Abstract Co-Author: Nothing to Disclose

Sughra Raza MD, Abstract Co-Author: Nothing to Disclose

To determine the outcome of ultrasound (US) detected breast masses prospectively categorized as BIRADS 3, 4, and 5, at our institution.

This is a retrospective review of breast US examinations with final interpretation of BIRADS 3, 4 or 5, performed between Jan 1, 2003 and April 30th, 2003. All exams were performed on one of two Philips ATL HDI 5000 machines using the L5-12, or CL15-5 MHz transducer. All examinations were performed by one of eight breast imaging radiologists.

Of the 190 breast US exams interpreted as BIRADS 3, 4 or 5, 35 were excluded due to BIRADS reflecting mammographic interpretation. The study included 155 lesions. BIRADS 3: N= 58; biopsy of 16/58 (27.6%) lesions revealed 1/58 (1.7%) 2mm invasive lobular carcinoma, 15/58 (25.9%) benign masses. On imaging follow-up 34/58 (58.6%) were stable at 6-24 months; 3/58 (5.2%) were follow-ups of known benign lesions, and remained stable; 5/58 (8.6%) were lost to follow-up. BIRADS 4: N=91; biopsy of 79/91 (86.8%) revealed 12/91 (13.2%) malignancies (11 with suspicious, 1 with benign US features) and 67/91 (73.6%) benign masses (21 with suspicious, 46 with benign US features). 6/91 (6.6%) patients had imaging follow-up, 2 resolved and 4 stable at 6-18 months. 6/91 (6.6%) patients were lost to follow-up. BIRADS 5: N=6; biopsy of 6/6 (100%) revealed malignancy, 4 invasive ductal,1 invasive lobular carcinoma, 1 ductal carcinoma in situ.

The positive biopsy rate (1.7%) of our BIRADS 3 group parallels the accepted cancer detection rate of mammographic BIRADS 3 lesions. Our low positive biopsy rate (13.2%) for BIRADS 4 lesions suggests that careful interpretation of US features and classification of these lesions according to the recent sub-categorization of BIRADS 4 lesions into a, b and c, will potentially lead to fewer benign biopsies. The positive biopsy rate of BIRADS 5 lesions was 100%.

Biopsy of some sonographically benign breast masses may be avoided with careful interpretation of US features and use of current BIRADS lexicon.

Nielsen, S, Birdwell, R, Raza, S, Sonographically Detected Breast Masses: Tracking BIRADS 3, 4, and 5 Lesions.  Radiological Society of North America 2006 Scientific Assembly and Annual Meeting, November 26 - December 1, 2006 ,Chicago IL. http://archive.rsna.org/2006/4435365.html