Malignant upgrade in lesions of uncertain malignant potential in the breast (B3 lesions) - is open excision always necessary?

Purpose: Unclear or suspicious breast findings are typically clarified by interventional breast biopsy. Lesions with uncertain malignant potential are grouped as B3 lesions in histopathology. The B3 group according to the European Working Group for Breast Screening Pathology (EWGBSP) comprises various breast lesions with different upgrade rates to invasive breast cancer (BC) or ductal carcinoma in situ (DCIS) if surgical removal is performed.