Mammography of the postsurgical breast.

Breast biopsy results in many radiographic abnormalities, some of which may be mistaken for carcinoma. A retrospective review of 4,023 mammographic examinations was undertaken to determine the incidence and natural history of postbiopsy changes, in order to provide background information helpful in differentiating postsurgical scarring from breast cancer. The study comprised 863 patients who had undergone biopsy before mammography (1,049 breasts). Abnormalities attributed to prior biopsy were found in 474 breasts (45%). Skin changes (thickening and deformity), architectural distortion, and parenchymal scars (poorly defined masses often with spiculated margins) were observed much less frequently 3 years after biopsy than they were within the first 6 months, suggesting that considerable resolution can be expected with time. All abnormal mammographic findings were detected in patients radiographed within 6 months of biopsy, most within 1-2 months of biopsy. These observations may be helpful, in carefully selected cases, in establishing the benign (i.e., postsurgical) nature of radiographic abnormalities that might otherwise be confused with malignancy.