Small Breast Cancer (≤ 5 mm): Ultrasonographic Features and Clinical and Pathological Characteristics

ABSTRACT

PURPOSE@#To identify differences in ultrasonography (US) feature, clinical and pathological characteristics including immunohistochemical characteristics between small breast cancer (pathologic size ≤ 5 mm) and large breast cancer (> 5 mm).@*MATERIALS AND METHODS@#A total of 528 invasive breast cancer lesions in 475 patients were included. US features with clinical and pathological characteristics were evaluated according to pathologic size. US Breast Imaging-Reporting and Data System findings and final assessments were recorded for each lesion. Standard references were based on surgical pathologies.@*RESULTS@#Of 528 invasive breast cancer lesions, 62 were small breast cancers. Small breast cancers showed a higher rate of oval, round shape, parallel orientation; circumscribed margin; and iso/solid and cystic echo pattern, with no posterior feature. The final assessment of category 4 was also a dominant factor in small breast cancer. Early stage, asymptomatic state, and extensive ductal carcinoma in situ component were associated with small breast cancers.@*CONCLUSION@#Our results show that small breast cancers have less suspicious US features than large breast cancers.