Malignant outcomes of architectural distortion on tomosynthesis: A systematic review and meta-analysis

BACKGROUND. The literature has reported varying rates of malignancy for architectural distortion (AD) on digital breast tomosynthesis (DBT). OBJECTIVE. The purpose of this study was to evaluate the PPV for malignancy of AD on DBT without a known cause and to assess the presence of an ultrasound (US) correlate for malignant AD through systematic review and meta-analysis of the literature. EVIDENCE ACQUISITION. This meta-analysis included all studies published in Embase, MEDLINE, and Evidence-Based Medicine Reviews databases through July 15, 2020, that assessed the rate of malignancy in patients with AD on DBT without a known cause that was deemed BI-RADS category 4 or 5. Rates of benign or high-risk lesions and the presence of a US correlate for malignant AD were assessed. Core needle biopsy or surgical pathology was used as the reference standard for lesion diagnosis. The pooled PPV and 95% CI were estimated using a random-effects model. EVIDENCE SYNTHESIS. Thirteen retrospective, observational studies were included, yielding 857 ADs seen on DBT. Of the 857 ADs, 339 were breast malignancies, yielding a pooled PPV for malignancy of 34.6% (95% CI, 24.5–46.3%). The pooled PPV for invasive malignancy was 34% (95% CI, 25–45%) and for ductal carcinoma in situ was 5% (95% CI, 4–7%). Of the 857 ADs, 235 (27.4%) were benign lesions, 282 (32.9%) were high-risk lesions, and 1 (0.1%) was a nonbreast metastatic lesion. From the studies that assessed for US correlates, 217 of 277 malignant ADs (78.3%) had a US correlate. CONCLUSION. The pooled PPV for malignancy of AD on DBT without a known cause is high at 34.6%, warranting tissue sampling. CLINICAL IMPACT. A needle biopsy should be performed for ADs on DBT without a known cause. Because most malignant distortions have a corresponding finding on US, a US examination should be performed to look for a correlate, but the absence of a correlate does not obviate a biopsy.