Benign and borderline phyllodes tumors of the breast: Clinicopathologic analysis of 205 cases with emphasis on the surgical margin status and local recurrence rate

Background: The management of benign and borderline phyllodes tumors of the breast with a positive surgical margin is still controversial. Our aim in this study was to evaluate the impact of surgical margin status on the local recurrence rate of benign and borderline phyllodes tumors. Methods: We reviewed 205 phyllodes tumors (191 benign, 14 borderline) that were surgically excised at our hospital between 2005 and 2019. Follow-up information extending to at least 6 months after surgery was retrieved from the clinical, radiology, and pathology records. Results: The initial surgical margin was negative in 54 (26%) cases, close (<= 1 mm) in 29 (14%) cases, and positive in 122 (60%) cases. Approximately half of the cases with a close margin and two-third of the cases with a positive margin underwent re-excision to obtain negative margins. Three (2.3%) local recurrences were observed among 131 cases with follow-up information, all three with benign phyllodes tumor. Of these three patients, one had a positive final margin, and two had negative final margins. There was no significant difference in the rate of local recurrence between PT with a positive surgical margin versus a close and negative margin. Conclusion: The study results suggest that close clinical and radiologic follow-up may provide a better course of management rather than re-excision when managing positive margins in benign and borderline phyllodes tumors.