Imaging Features of Nonmalignant and Malignant Architectural Distortion Detected by Tomosynthesis

The objective of our study was to determine the ability of tomosynthesis (3D) to detect nonmalignant and malignant architectural distortion (AD) on 3D screening mammograms compared with digital mammography (2D) only and to correlate the 3D imaging features of nonmalignant and malignant AD with pathology findings.

For this single-institution retrospective study, screening mammography reports from October 1, 2012, to December 1, 2016, that included AD as a finding were reviewed. Associated additional imaging studies and pathology results were also reviewed.

Three-dimensional mammography showed statistically significant increased detection of both nonmalignant and malignant AD compared with 2D only (0.10% [24/24,902 examinations] vs 0.01% [1/9470 examinations], p < 0.05; and 0.21% [52/24,902 examinations] vs 0.07% [7/9470 examinations], p < 0.05, respectively). Higher percentages of nonmalignant AD (16%) were occult on ultrasound compared with malignant AD (3%). The pathologic diagnoses of nonmalignant AD included radial scar (42%), sclerosing adenosis (16%), stromal or dense fibrosis (16%), and other miscellaneous benign causes (25%). Morphologically, nonmalignant AD was more likely to show symmetric or spoke-wheel spiculation appearance (58% vs 2%, p < 0.05) and central lucency (25% vs 0%, p < 0.05) than malignant AD, whereas malignant AD was more likely to show asymmetric spiculation (98% vs 42%, p < 0.05) and central mass 60% vs 0%, p < 0.05) than nonmalignant AD.

Malignant AD and nonmalignant AD are more readily detected by 3D mammography than 2D mammography. Three-dimensional imaging features of AD can help to distinguish nonmalignant types in which symmetric or spoke-wheel spiculation with central lucency are more often seen and are more often occult on ultrasound.