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: To evaluate the positive predictive value (PPV) for malignancy of AD on DBT without a known etiology, 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 (EBM) reviews through July 15, 2020 that assessed the rate of malignancy in patients with AD on DBT without a known cause and that were deemed Breast Imaging-Reporting and Data System (BI-RADS) 4 or 5. Rates of benign or high-risk lesions and presence of an 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 its 95% confidence interval (CI) were estimated using a random-effects model. Evidence Synthesis: Thirteen retrospective, observational studies were included, yielding 857 AD seen on DBT. There were a total of 339/857 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%). The pooled PPV for ductal carcinoma in situ was 5% (95% CI: 4%-7%). There were 27.4% (235/857) benign lesions, 32.9% (282/857) high-risk lesions, and 0.1% (1/857) non-breast metastatic lesion. A total of 78.3% (217/277) of malignant AD had an US correlate. Conclusion: Pooled PPV for malignancy of AD without a known cause on DBT is high at 34.6%, warranting tissue sampling. Clinical Impact: A needle biopsy should be performed for AD on DBT without a known etiology. Since most malignant distortions have an US finding, an US examination should be performed to look for a correlate, but the absence of a correlate does not obviate the need for a biopsy.