Madhavi Raghu MD, Presenter: Nothing to Disclose

Jaime Lynn Geisel MD, Abstract Co-Author: Consultant, Siemens AG

Regina J. Hooley MD, Abstract Co-Author: Nothing to Disclose

Reni Simov Butler MD, Abstract Co-Author: Nothing to Disclose

Melissa Angeline Durand MD, Abstract Co-Author: Nothing to Disclose

Liane Elizabeth Philpotts MD, Abstract Co-Author: Nothing to Disclose

Tomosynthesis has been shown to improve diagnostic confidence with fewer mammographic follow-up recommendations (BI-RADS (BR) 3). As this rate declines, the criteria for lesions previously thought to be probably benign may need to be re-evaluated. The purpose of this study was to determine the number, type and mammographic manifestations of malignancies detected with diagnostic mammograms performed with tomosynthesis, which were previously categorized as BR3.

A retrospective review of all BR 3 diagnostic mammograms performed with tomosynthesis from Jan 2012 to June 2013 was conducted. Follow up data at 6-12 months was obtained and all studies re-classified as BR 4,5 with subsequent malignant outcomes were evaluated. The size, histology, US correlate and mammographic finding (asymmetry, calcifications, mass or architectural distortion) was reviewed for each malignancy.

5893 diagnostic mammograms were performed of which 1391 (23.6%) were categorized as BR3. These 1391 patients had 1688 findings: calcifications (658), asymmetries (511), masses (472), and architectural distortions (47). At the 6-12 month follow-up interval, 35 studies were re-classified as BR 4 or 5 resulting in 6 (0.5%) malignancies: 2 (2/472; 0.4%) 5 mm masses (stage I) appeared more suspicious on US at the 6 month interval and biopsy of both masses showed IDC. One patient (1/47;2%) presented with one view architectural distortion, not seen on US. Subsequent MRI demonstrated a 5 mm spiculated mass, which yielded IDC (stage I) at biopsy. Three patients (3/658;0.4%) had calcifications (2 of which were 6 mm and one 2 cm), which were more prominent at the 6 month interval and biopsy revealed DCIS. None of the asymmetries recommended for short interval follow-up resulted in malignancy.

The malignancy rate of all BR3 studies was low at 0.5%. All malignancies were early stage and evident as masses or calcifications. Therefore with tomosynthesis some calcifications, masses and architectural distortions may be appropriate for follow-up but benign appearing asymmetries likely do not need to be followed.

Mammography with tomosynthesis is becoming an integral aspect of the diagnostic setting improving specificity and will ultimately redefine the BI-RADS criteria particularly for probably benign lesions.

Raghu, M, Geisel, J, Hooley, R, Butler, R, Durand, M, Philpotts, L, Malignancy in BI-RADS 3 Studies Performed with Tomosynthesis.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14015454.html