Pathologic Outcomes of Architectural Distortion on Digital 2D Versus Tomosynthesis Mammography.

OBJECTIVE: The purpose of this study is to compare the risk of malignancy associated with architectural distortion detected on 2D digital mammography (DM) versus digital breast tomosynthesis (DBT).

MATERIALS AND METHODS: We performed a retrospective review of architectural distortion cases recommended for biopsy from September 2007 to February 2011, the period before DBT integration (hereafter known as the DM group), and from January 2013 to June 2016, the period after DBT integration (hereafter known as the DBT group). Medical records were reviewed for imaging findings and pathology results.

RESULTS: Architectural distortion was more commonly detected in the DBT group than the DM group (0.14% [274/202,438 examinations] vs 0.07% [121/166,661 examinations]; p < 0.001). The positive predictive value of architectural distortion for malignancy was significantly lower in the DBT group than the DM group (50.7% [139/274 cases] vs 73.6% [89/121 cases]; p < 0.001). Radial scar was the most common nonmalignant finding in both groups, but it was more common in the DBT group (33.2% [91/274] vs 11.6% [14/121]; p < 0.001). In the DBT group, architectural distortion without correlative findings on ultrasound was less likely to represent malignancy than was architectural distortion with correlative findings on ultrasound (29.2% [31/106] vs 66.5% [105/158]; p < 0.001).

CONCLUSION: Architectural distortion is more commonly detected on DBT than DM and is less likely to represent malignancy on DBT. Architectural distortion on DBT is less likely to represent malignancy if there is no sonographic correlate; however, biopsy is warranted even in the absence of a sonographic correlate, given the nearly 30% risk of malignancy in this setting.