Magnetic resonance imaging of ductal carcinoma in situ

Intraductal cancer or ductal carcinoma in situ (DCIS) has been considered a mammographic disease. Before the advent of mammographic screening, only about 2% to 5% of breast cancers were diagnosed in the intraductal stage. Magnetic resonance imaging (MRI) has traditionally been considered insensitive for DCIS. More recent studies, however, suggest that, with appropriate diagnostic criteria, contrast-enhanced MRI may be a very sensitive tool for diagnosing DCIS, especially high-grade DCIS. In addition, MRI has been shown to be superior to delineate the intraductal extension of invasive cancers – another reason why preoperative staging with MRI is important. The likelihood with which the mammographic diagnosis of DCIS or DCIS components fails does not correlate with mammographic breast density – in other words, a missed mammographic diagnosis of DCIS is also conceivable in women with involuted breast. The present lecture summarizes the current level of evidence, and discusses the clinical implications of these findings.