Noninvasive breast cancer comprises two distinct entities, lobular carcinoma in situ (LCIS) and ductal carcinoma in situ (DCIS). The increased use of screening mammography has caused more cases of noninvasive breast cancer to be discovered. However, the increased detection of LCIS and DCIS has posed problems in patient care for the radiologist, pathologist, surgeon, radiation oncologist, and medical oncologist. The authors review the past history of LCIS and DCIS, as well as the diagnostic challenges and therapeutic considerations for the multidisciplinary breast cancer team.