Phyllodes tumors of the breast in 2 sisters

RATIONALE Phyllodes tumors (PT) of the breast are rare neoplasm originating from fibroepithelial component. To our knowledge, our report is the first reported case of PT in 2 sisters. PATIENT CONCERNS We presented 2 cases of PT of the breast involving in 2 sisters. On physical examination of the younger sister, a firm mass measuring approximately 3 cm in diameter was identified in upper inner quadrant of the right breast. Physical examination of the elder sister revealed a 3 cm lump in upper outer quadrant of the left breast. DIAGNOSES Histopathology of the younger sister revealed a malignant PT. The elder sister was diagnosed with borderline PT. INTERVENTIONS The younger sister with malignant PT underwent right mastectomy. The elder sister with borderline PT was scheduled for wide resection of the mass in the left breast. OUTCOMES After a follow-up of 23 months, no local or distant recurrence was observed. LESSONS Our cases indicate that genetic factor may contribute to the risk of PT of the breast. Markers such as p53 and Ki-67 may have some correlation with PT malignancy.