ABSTRACT
BACKGROUND: Phyllodes tumors are rare breast neoplasms and the histopathological grade and surgical margins help guide treatment and follow-up. The traditional surgical teaching is resection with ≥10 mm margins, but are narrower surgical margins acceptable? The purpose of our study was to identify predictors of local recurrence. METHODS: A retrospective analysis was performed to identify patients with phyllodes tumors who underwent surgery between 2002 and 2014 using a regional pathology database. Electronic medical records were used to identify surgical management, pathological characteristics, and follow-up encounters. RESULTS: A total of 150 phyllodes tumors were included: 110 of 150 (73%) benign, 21 of 150 (14%) borderline, and 19 of 150 (13%) malignant. At initial surgery, 29 specimens had a positive margin and 15 (56%) underwent re-excision. Seventy tumors had a surgical margin of ≤1 mm, 40 had a margin of 2 to 9 mm, and 11 had a margin of ≥10 mm. There were 11 of 150 (7.3%) locally recurrent tumors: 5 of 11 (45%) benign, 3 of 11 (27%) borderline, and 3 of 11 (27%) malignant. In total, 10 of 11 locally recurrent tumors had a positive margin or ≤1 mm margin at initial surgery. CONCLUSIONS: Phyllodes tumors can have a personalized treatment approach based on histopathological grade and surgical margins. Borderline and malignant phyllodes tumors with a positive or ≤1 mm surgical margin have an increased risk of recurrence. In benign phyllodes tumors, an optimal narrow negative margin may exist but the traditional ≥10 mm excisional margin is not necessary. Local recurrence rates may be sufficiently low in benign phyllodes tumors that imaging can be performed on the presence of clinical symptoms.