Low Grade Malignant (Borderline) Phyllodes Tumor of the Breast: Case Report and Review of Literature

Abstract

Phyllodes tumor (PT) of the breast is a rare disease usually presents as a large lump. The aim of this study was to report low grade malignant (borderline) PT of the breast in Kermanshah, Iran. A 55-year-old lady was admitted to the surgery ward with left breast mass since 2-3 months ago. In past medical history, the patient had left breast surgery due to fibrocystic change seven years ago. Grossly her specimen consisted in a piece of gray soft tissue measuring 10*8*4.5 cm with lobulated appearance and small cystic areas. In permanent diagnosis, the pathologist reported low-grade malignant (borderline) PT. Microscopically the tumor was composed of benign glandular elements and hypercellular spindle-shaped stroma. Mitotic index was 3/10 high power field (HPF). The border was well-circumscribed with satellite lesion. In conclusion, the diagnosis of borderline phyllodes tumor cannot be made only on age, the size of tumor, imaging or clinical features. Microscopic evaluation with evaluation of stromal cellularity, atypia, mitotic counts and border of the tumor is necessary for definite diagnosis and categorizing of this tumor.