Findings: A large well-defined lobulated solid mass measuring about 14 x 12 x 11 cm is seen in the left breast. Multiple branching fibrotic bands are seen within this mass. No spiculations, cystic areas or obvious calcifications are seen in it. The overlying skin is stretched but not thickened. No nipple retraction is noted. No evidence of infiltration of the underlying pectoral muscles. No significant left axillary lymphadenopathy is seen. Mass shows significant enhancement on the dynamic post-contrast scan with type I curve. Right breast is unremarkable. Impression: Large well-defined, lobulated solid left breast mass with benign enhancement curves. Possible differential diagnoses include giant fibroadenoma and phyllodes tumor.