Role of ultrasound-guided vacuum-assisted breast biopsy in the management of radiologic-pathologic discordance: a retrospective single-centre study

Purpose: To evaluate the efficacy of US-guided vacuum-assisted biopsy (US-VAB) in radiologic-pathologic (rad-path) discordance in women with suspicious breast lesions. Methods: Two thousand three hundred and sixty patients with 2385 BI-RADS category 4 and 5 lesions underwent percutaneous US-guided CNB. Thirty-six lesions were classified as discordant benign and underwent second-line US-VAB. A 14-gauge needle was utilized for CNB and 10-gauge for US-VAB. Final pathology was the reference standard for women who underwent surgery, imaging follow-up in other cases. Rates of malignancy for US-VAB and subsequent surgery were evaluated. Lesions with upgrade and no upgrade to second-line VAB were compared in terms of patient's age, lesion type and characteristics, size and BI-RADS category. Positive predictive value (PPV), negative predictive value (NPV) for BI-RADS categories and diagnostic performance for second-line US-VAB were calculated. p value < 0.05 was considered statistically significant (t-test, Mann-Whitney, chi(2)). Results: US-VAB identified 10 B2, 9 B3 and 17 B5 lesions with upgrade to malignancy of 47.2% (17/36). There were 8 invasive no special type, 7 ductal in situ, 1 invasive lobular carcinoma and 1 angiosarcoma, and their distribution among BI-RADS categories was: 2/2 in BI-RADS 5 (100%), 12/18 in BI-RADS 4C (67%) and 3/16 in BI-RADS 4B lesions (19%) (p = 0.006). Of the remaining 19 lesions, 6 underwent surgery and 2 were upgraded to ductal carcinoma in situ; 13 underwent radiological follow-up and one resulted malignant. False-negative rate for US-VAB was 15.8% (3/19) with final upgrade to malignancy of 55% (20/36). The univariate analysis revealed mass shape (p = 0.008) and BI-RADS categories (p = 0.006) to be associated with upgrade to malignancy. Sensitivity, specificity, PPV, NPV and accuracy for US-VAB were 85, 100, 100, 84 and 92%, respectively. Conclusions: US-VAB identified almost 50% of cancers missed by CNB, avoiding surgical biopsies and validating as an effective mini-invasive approach in rad-path discordance.