Papillary lesions of breast on core-needle biopsy: Factors associated with malignant upgrade on surgical excision

Papillary lesions (PLs) of the breast diagnosed on core-needle biopsy (CNB) pose a management dilemma due to their variable upgrade rates to malignancy. This study aims to identify predictors of malignant upgrade, facilitating risk stratification that may spare low-risk patients from unnecessary open surgery.

This retrospective study analyzed 219 CNB-diagnosed PLs in 172 female patients at a tertiary center from 2008 to 2022. Clinical parameters (age at diagnosis, single duct bloody nipple discharge, mastalgia), sonographic findings (multifocality, size, location, intraductal lesion, intralesional vascularity, margin, posterior features) and histopathologic findings (atypia) were analyzed with Fisher's exact test and multivariate logistic regression.

The overall upgrade rate to malignancy was 8.2% (18/219). Four independent predictors of upgrade were identified: lesion size ≥1 cm (Odds ratio [OR] 3.6, 95% confidence interval [CI] 1.0-12.3; p = 0.045), intralesional vascularity (OR 7.0, 95% CI 2.2-22.5; p = 0.001), non-circumscribed margins (OR 6.4, 95% CI 1.5-27.7; p = 0.013), and atypia (OR 6.6, 95% CI 1.9-23.2; p = 0.003). Subcentimeter circumscribed lesions without atypia and vascularity had a 3.4% upgrade rate (3/88) and 96.6% negative predictive value.

Lesion size ≥1 cm, presence of intralesional vascularity, non-circumscribed margins, and atypia on CNB specimens are significant predictors of malignant upgrade in patients with PLs on CNB. Low-risk lesions (subcentimeter circumscribed lesions without vascularity and atypia) may be managed with minimally invasive approaches (e.g., vacuum-assisted excision) given their low upgrade rate (3.4%) and high negative predictive value (96.6%), while high-risk lesions (particularly those with atypia) warrant surgical excision.