Yu X, et al. - Researchers analyzed pre-operative ultrasonographic images of 153 small breast malignant neoplasms in 143 breast cancer patients according to their pathologic features in order to study the correlation of ultrasonographic signs of small breast cancer (maximum diameter ≤2.0 cm) with axillary lymph node metastasis. In small breast cancer, characteristics such as perforating vessels and maximum cortical thickness of lymph nodes >3.0 mm seemed to have a correlation with axillary lymph node metastasis.