Invasive breast cancer: Mammographic measurement

PURPOSE: To establish the accuracy of mammographic measurement of tumor size for invasive carcinoma. MATERIALS AND METHODS: For 85 invasive cancers, mammographic tumor size was determined as the largest dimension observed on any mammographic projection (craniocaudal, lateral, or mediolateral oblique). This was then compared with the largest tumor dimension in the gross specimen. RESULTS: The relationship between the mammographic size and the pathologic size was almost exactly 1:1, with low variability. Mammographic measurements were larger by an average of about 1 mm. Neither breast parenchymal pattern nor the presence of accompanying ductal carcinoma in situ affected accuracy. CONCLUSION: Mammography can allow tumor size to be measured accurately and can be used as an alternative when pathologic staging is not possible.