Audit on Intraductal Papilloma of the Breast: Upgrade Rate, Management Pitfalls, and Updated Guidelines in a Tertiary Health Care Center.

ABSTRACT

Background Intraductal papillomas (IDPs) are typically classified as B3 lesions in histology as they may show intralesional heterogeneity with a potential upgrade to malignancy. On core needle biopsy (CNB), a distinction between papilloma versus papillary ductal carcinoma in situ (DCIS) may be difficult. It is well known that otherwise benign papillomas may harbor foci of atypical ductal hyperplasia or DCIS. In this study, we aimed to calculate the radiological (mammogram and ultrasound) accuracy of IDP and to analyze the accuracy of CNB to diagnose IDP. Furthermore, we calculated the percentage of upgrade to malignancy after surgical excision. Any case that had a co-existing in-situ or invasive carcinoma during surgical excision was considered as an "upgrade" to malignancy. Finally, we analyzed the current management protocol for IDP in the institution and suggested changes, if needed. Methodology This is a retrospective cross-sectional study. A total of 112 cases diagnosed as IDP radiologically and/or by histopathology over a one-year time frame were included. A retrospective analysis of the accuracy of the radiological diagnosis was done by comparing it with CNB and/or surgical excision biopsy reports. The number of cases diagnosed with a co-existing in-situ or invasive carcinoma was calculated. This was considered as an "upgrade" from a B3 lesion in CNB to carcinoma in surgical excision. Current institutional management protocols were evaluated and compared with international benchmarks. Results Out of the 112 cases, 91 were suspected to be papilloma by imaging. The remaining 21 cases who were positive for papilloma on biopsy but were not diagnosed radiologically were also studied separately. Among the biopsied patients, eight were positive for IDP with atypia in CNB. Five out of these eight cases had an in-situ or invasive component during the surgical excision, with one invasive lobular carcinoma, three lobular carcinomas in situ, and one DCIS on surgical excision histopathology. The upgrade percentage was calculated to be 22.72%. Conclusions Due to the large upgrade potential of IDP, it is recommended to biopsy every radiologically suspected lesion and excise pathology-proved lesions. If the biopsy shows papilloma without atypia, vacuum excision is sufficient; otherwise, surgical excision with a clearance of margins is advocated. Annual mammograms/surveillance is recommended for biopsy-proven cases. IDP has a high upgrade potential, and, hence, care should be taken to biopsy suspicious lesions. An excision of biopsy-proven lesions must be done.