Ductal carcinoma in situ is considered the earliest form of breast cancer. It's characterized by the presence of abnormal cells inside a milk duct in the breast. It's noninvasive, meaning it hasn't spread out of the milk duct and has a low risk of becoming invasive.
This early form of breast cancer typically doesn't show any signs or symptoms. It usually is found during a mammogram performed as part of breast cancer screening or to investigate a breast lump. Treatment has a high likelihood of success.
Learn more about the diagnosis and treatment options for ductal carcinoma in situ.