Minimal invasive biopsy results of "uncertain malignant potential" in digital mammography screening: high prevalence but also high predictive value for malignancy.

PURPOSE: To evaluate the rate, the histological spectrum and the positive predictive value (PPV) for malignancy of minimally invasive biopsies with "uncertain malignant potential (B3)" in digital mammography screening. METHODS AND MATERIALS: Consecutive data of 37,178 participants of one digital unit of the German screening program were included.
RESULTS: The B 3 rate was 15.1 % (148 / 979). The frequencies of lesion subtypes were as follows: atypical epithelial proliferation of ductal type (AEPDT) 35.1 % (52 / 148), radial scar (RS) 28.4 % (42 / 148), papillary lesions (PAP) 20.3 % (30 / 148), lobular carcinoma in situ 8.8 % (13 / 148), flat epithelial atypia 5.4 % (8 / 148), and mucocele-like lesions 2.0 % (3 / 148). The PPV for malignancy in surgical excisions was overall 0.28 (25 / 91); in detail 0.40 (19 / 47) for AEPDT, 0.20 (5 / 25) for RS, 0.08 (1 / 12) for PAP.
CONCLUSION: Despite a higher B 3 rate of minimally invasive biopsies with "uncertain malignant potential" in digital screening, the benign surgical biopsy rate is not disproportionally increased compared with analog screening programs. Together with defined management protocols, this results in an increased cancer detection rate per screening participant with surgical excision. © Georg Thieme Verlag KG Stuttgart · New York.