Atypical epithelial hyperplasia, lobular carcinoma in situ (lobular neoplasia), radial scar, and ductal carcinoma in situ are considered high-risk lesions that predispose toward the future development of non-invasive or invasive breast cancer. Generally, those women with atypical epithelial hyperplasia, radial scar, or lobular carcinoma in situ can be managed conservatively by close surveillance. The minority of women may consider prophylactic mastectomy. Ductal carcinoma in situ can usually be managed by lumpectomy with or without radiation, with some patients requiring mastectomy due to extensive disease.