Phyllodes tumors of the breast in 2 sisters: Case report and review of literature.

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.