Clinical breast echography is increasingly being used as it offers a high degree of diagnostic accuracy rate. Internal echoes of usual breast cancer is hypoechoic in the majority of cases, however hyperechoic mass lesion may appear in rare instances. This echo-pattern was seen in a 38-year-old housewife with invasive ductal carcinoma. Also, its bio-acoustical mechanism, that is, why hyperechoic pattern appears, was investigated from the viewpoint of ultrasonic tissue characterization and its related papers were reviewed. Tumor heterogeneity in cellularity such as cribriform pattern, tubular structure, solid nests and a scirrhous pattern of cancer cells may play an important role in producing the hyperechoic breast pattern.