Malignancy Rate and Malignancy Risk Assessment in Different Lesions of Uncertain Malignant Potential in the Breast (B3 Lesions): An Analysis of 192 Cases from a Single Institution

Svjetlana Mohrmann; Anna Maier-Bode; Frederic Dietzel; Petra Reinecke; Natalia Krawczyk; Thomas Kaleta; Ulrike Kreimer; Gerald Antoch; Tanja N Fehm; Katrin Sabine Roth

doi:10.1159/000517109

Malignancy Rate and Malignancy Risk Assessment in Different Lesions of Uncertain Malignant Potential in the Breast (B3 Lesions): An Analysis of 192 Cases from a Single Institution

Breast Care (Basel). 2022 Apr;17(2):159-165. doi: 10.1159/000517109. Epub 2021 Jul 1.

Authors

Affiliations

¹ Department of Gynecology and Obstetrics, Medical Faculty, Interdisciplinary Breast Centre, University of Düsseldorf, Düsseldorf, Germany.
² Department of Diagnostic and Interventional Radiology, Medical Faculty, University of Düsseldorf, Düsseldorf, Germany.
³ Institute of Pathology, Medical Faculty, University of Düsseldorf, Düsseldorf, Germany.
⁴ ZRN Rheinland, Center for Radiology and Nuclear Medicine, Korschenbroich, Germany.

Abstract

Background: The question of how to deal with B3 lesions is of emerging interest.

Methods: In the breast diagnostics of 192 patients between 2009 and 2016, a minimally invasive biopsy revealed a B3 lesion with subsequent resection. This study investigates the malignancy rate of different B3 subgroups and the risk factors that play a role in obtaining a malignant finding.

Results: The distribution of B3 lesions after minimally invasive biopsy was as follows: atypical ductal hyperplasia (ADH), 7.3%; flat epithelial atypia (FEA), 7.8%; lobular neoplasia (LN), 7.8%; papilloma (Pa), 49.5%; phylloidal tumour (PT), 8.9%; radial sclerosing scar (RS), 3.1%; mixed findings, 10.4%; and other B3 lesions, 5.2%. Most B3 lesions were detected by stereotactic vacuum-assisted biopsy (44.3%), 36.5% by ultrasound-assisted biopsy, and 19.3% by magnetic resonance imaging-assisted biopsy. Most B3 lesions (55.2%) were verified by surgical resection, whereas 30.7% were downgraded to a benign lesion. About 14.1% of the cases were upgraded to malignant lesions, 9.4% to ductal carcinoma in situ and 4.7% to invasive carcinoma. In relation to individual B3 lesions, the following malignancy rates were found: 28.6% (ADH), 13.3% (FEA), 33.3% (LN), 12.6% (Pa), 5.9% (PT), and 0% (RS). The most important risk factor was increasing age. Postmenopausal status was considered an increased risk for an upgrade (p = 0.015). A known malignancy in the ipsilateral breast was a significant risk factor for a malignant upgrade (p = 0.003).

Conclusion: Increasing knowledge about B3 lesions allows us to develop a "lesion-specific" therapy approach in the heterogeneous group of B3 lesions, with follow-up imaging for some lesions with less malignant potential and concordance with imaging or further surgical resection in cases of disconcordance with imaging or higher malignant potential.

Keywords: B3 lesion; Breast surgery; Malignancy rate; Risk factors; Therapy.