Background: Breast lesions not sampled prior to surgery or initially diagnosed as fibroepithelial lesions on core biopsy may have a diagnosis of phyllodes tumor (PT) on excision. Historically, re-excision for close or positive margins has been the standard of care. We examined the rate of re-excision for close or positive margins in patients with benign phyllodes and compared recurrence rates among those undergoing re-excision versus observation.
Methods: We identified all patients with phyllodes tumor diagnosed between 2003 and 2013. Operative and surgical pathology reports were reviewed for clinical, pathologic, and follow-up data.
Results: Among 246 cases, 216 (88%) were benign PT and 30 (12%) borderline/malignant tumors. In the group of benign PT (n = 216), margins were negative in 64 patients (29.6%), 50 (23%) were close, and 102 (47%) were positive. Of those with close margins, 22 (44%) underwent reexcision and residual benign PT was found in 2 (9%). In patients with positive margins, 45 (44%) had re-excision and residual benign PT was detected in 4 (8.8%). After a median follow-up of 35.5 months, there were 4 (1.9%) recurrences among patients with benign PT. There was no difference in recurrence among patients who had re-excision for positive or close margins versus observation (p = 0.7 and 0.21, respectively).
Conclusions: Among patients with close or positive margins, there was no significant difference in disease recurrence between patients who underwent reexcision and those who were observed. Based on these results, it may be reasonable to manage these patients conservatively with close follow-up.