Analysis of 612 Benign Papillomas Diagnosed at Core Biopsy: Rate of Upgrade to Malignancy, Factors Associated With Upgrade, and a Proposal for Selective Surgical Excision.

BACKGROUND. Despite numerous published studies, management of benign papillomas without atypia remains controversial. OBJECTIVE. The purpose of this study was to determine the malignancy upgrade rate of benign papillomas, identify risk factors for upgrade, and formulate criteria for selective surgery. METHODS. This retrospective study included benign papillomas without atypia diagnosed on percutaneous biopsy between December 1, 2000, and December 31, 2019. Papillomas that did not undergo surgical excision or at least 2 years of imaging and/or clinical follow-up were excluded. Clinical, imaging, and histopathologic features were extracted from the electronic medical record. Features associated with upgrade to malignancy were identified. Multivariable logistic regression was performed. RESULTS. The study included 612 benign papillomas in 543 women (mean age, 54.5 ± 12.1 [SD] years); 466 papillomas were excised, and 146 underwent imaging or clinical surveillance. The upgrade rate to malignancy was 2.3% (14/612). Upgrade rate was associated ( p < .05) with radiology-pathology correlation (50.0% if discordant vs 2.1% if concordant), patient age (5.6% for 60 years and older vs 0.7% for younger than 60 years), presenting symptoms (6.7% if palpable mass or pathologic nipple discharge vs 1.3% if no symptoms), and lesion size (7.3% if ≥ 10 mm vs 0.6% if < 10 mm). Three of 14 upgraded papillomas were associated with four or more metachronous or concurrent peripheral papillomas. No incidental papilloma or papilloma reported as completely excised on core biopsy histopathologic analysis was upgraded. A predictive model combining radiology-pathology discordance, symptoms (palpable mass or nipple discharge), age 60 years old and older, size 10 mm or larger, and presence of four or more metachronous or concurrent peripheral papillomas achieved an AUC of 0.91, sensitivity of 79%, and spec-ificity of 89% for upgrade. Selective surgery based on presence of any of these five factors, although excluding from surgery incidental papillomas and papillomas reported as completely excised on histopathology, would have spared 294 of 612 lesions from routine excision and identified all 14 upgraded lesions. CONCLUSION. Benign nonatypical papillomas have a low malignancy upgrade rate; routine surgical excision may not be necessary. Selective excision is recommended for lesions satisfying any of the five criteria. Incidental papillomas or papillomas completely excised on histopathology may undergo imaging follow-up. CLINICAL IMPACT. The proposed criteria for selective surgery of benign papillomas on core biopsy would reduce surgeries without delaying diagnosis of malignancy.