The objective of this article is to explain radiologic patterns of benign and malignant breast lesions (masses, microcalcifications) based on histological correlations. The stromal fibrous reaction associated to infiltrating carcinomas is responsible of focal increased density, and architectural distorsion, ultrasound acoustic shadowing; abnormal neoangiogenesis can be detected by Doppler, CT or MR imaging. Invasive carcinomas without spiculated margins are poorly differentiated tumors. Mammographic patterns of microcalcifications depend on their physiopathological process (necrosis, secretion), and the shape of clusters (round, triangular) typifies their anatomical site of origin (lobular, ductal). Less frequent lesions (invasive lobular, mucinous, and medullary carcinomas, radial scar) will be also explained based on radiopathological correlations. Knowledge of radiopathological correlations in breast diseases helps the radiologists to analyze and characterize breast lesions.