The implications of the imaging manifestations of multifocal and diffuse breast cancers

Mammographic screening of asymptomatic women leads to the detection of an unprecedented number of in situ and nonpalpable 1-9 mm and 10-14 mm invasive breast cancers. Detecting breast cancer at an earlier phase in its development and at a smaller tumor size is, however, no guarantee that the disease will be localized to a small, confined volume in every case. In fact, multifocal and/or diffuse breast cancers comprise the majority of breast cancers in every size range (Holland et al. 1985; Tot 2007). These studies have also shown that the frequency of unifocal and multifocal breast cancers is unaffected by tumor size at detection (Table 7.1).