An Example of Breast Cancer Regression on Imaging

Controversy exists as to whether some breast cancers spontaneously regress without treatment. Regression of malignant breast neoplasms contradicts the long-accepted natural history of the disease and may have implications on the efficacy of breast cancer screening programs. We present a case in which a breast cancer regressed following cessation of hormone replacement therapy and consider the biologic basis and implications of breast neoplasms that depart from the accepted model of progressive tumor growth.