Ultrasound (US) of the breast will accurately measure breast tumor size when compared with size as determined by pathologic examination.
Retrospective case series.
University hospital–based breast center.
Thirty-five women with a diagnosis of breast cancer who had US as a component of their evaluation.
Main Outcome Measure
Tumor size as measured by US compared with size measured by pathologic examination.
Size measured by US ranged from 0.45 to 3.81 cm. Size measured by pathologic examination ranged from 0.5 to 5 cm. The mean difference of size measured by US vs pathologic size was 0.4 cm (P = .01). When only tumors with invasive ductal histology are evaluated, the mean difference in size is 0.33 cm (P = .008). The range of difference was −1.6 cm to +0.42 cm. Seventeen percent of invasive ductal tumors were underestimated by more than 1 cm; none were underestimated by more than 2 cm.
This study demonstrates that, although US tends to underestimate the pathologic tumor size, 83% of invasive ductal tumors fall within a 1-cm and 100% fall within a 2-cm extension of the US-measured tumor size. Therefore, it is possible to use US to monitor the extent of treatment size when developing very localized therapeutic tools.