Single-institution outcomes after excision of benign phyllodes tumors: low recurrence risk even with positive margins

Purpose Benign phyllodes tumors (BPT) are rare breast neoplasms with clinical behavior that poses low recurrence risk. Guidelines regarding appropriate margins recommend surgical excision to negative margins, sometimes requiring re-excision surgery. Contemporary experience suggests that re-excision in the face of positive margins may not be needed. Methods This is a retrospective review of a single-institution experience with BPT from 2010 to 2019 with 102 patients. Demographics, outcomes and follow-up were analyzed. Results The median age was 37 years. 95% had a pre-operative biopsy and only 6% were confirmed BPT before surgery.56% had positive margins and were more likely to be younger and have a pre-operative diagnosis of fibroadenoma. The median follow-up was 33 months. Between the positive and negative margin groups, recurrence rates were not significantly different ( p = 0.87). Conclusion Positive margins on excision of BPT poses a low recurrence risk and re-excision surgery is not necessary.