Factors associated with histologic upgrade following surgical excision of breast papillomas: a retrospective multicenter study

PURPOSE: This study aimed to determine malignant, high-risk, and overall diagnostic upgrade rates after surgical excision of image-guided biopsy-proven intraductal papillomas and to identify factors associated with overall diagnostic upgrade. METHODS: In this retrospective multicenter study, 527 surgically excised papillary lesions from 30 centers were evaluated. Malignant upgrade was defined as malignancy at excision after a biopsy diagnosis of papilloma with or without atypia; high-risk upgrade was defined as a high-risk lesion at excision after papilloma without atypia. Overall diagnostic upgrade comprised either outcome. Multivariable logistic regression assessed age, lesion size, risk status, presence of symptoms, and radiologic-pathologic concordance. RESULTS: Papilloma without atypia accounted for 407 lesions, and papilloma with atypia for 120. The overall malignant upgrade rate was 21.4% (113/527). Among papillomas without atypia, high-risk and malignant upgrade rates were 19.7% (80/407) and 14.2% (58/407), respectively; among papillomas with atypia, malignant upgrade was 45.8% (55/120). Overall diagnostic upgrade occurred in 36.6% (193/527). Multivariable analysis identified older age [odds ratio (OR), 1.03 per year; 95% confidence interval (CI), 1.02-1.05], larger lesion size (OR, 1.02 per mm; 95% CI, 1.00-1.03), presence of symptoms (OR, 1.69; 95% CI, 1.15-2.49), and radiologic-pathologic discordance (concordance OR, 0.54; 95% CI, 0.35-0.84) as independent predictors of upgrade. Microcalcifications (OR, 2.47; 95% CI, 1.27-4.85) and asymmetry (OR, 2.18; 95% CI, 1.12-4.25) on mammography were also significantly associated with upgrade. CONCLUSION: In this retrospective multicenter cohort of surgically excised, biopsy-proven papillary lesions, atypia and several clinical and imaging factors were associated with diagnostic upgrade. These findings may support individualized management decisions in patients with papillary breast lesions. CLINICAL SIGNIFICANCE: Identifying clinical and imaging predictors of upgrade may facilitate risk-adapted management of papillary breast lesions and help avoid unnecessary surgical excision in carefully selected patients.