Evaluation of cortical contour of suspicious axillary lymph nodes using ultrasound among various molecular subtypes of breast cancer

: In this study, we assessed specific morphological features of axillary lymph nodes, including the longitudinal axis to short axis ratio, distortion of the corticomedullary interface, cortical contour, nodal core sign, and perinodal hyperechogenic ring using a high-frequency linear probe. Among these features, the p-value was significant for cortical contour, warranting special emphasis. This focus on cortical contour may help reduce the need for immunohistochemistry in the future, proportionately lowering associated costs. : To evaluate B-mode ultrasound features of suspicious axillary lymph nodes in histopathologically proven cases of breast cancer and assess whether these features vary between different molecular subtypes of breast cancer. A total of 74 patients with histopathologically confirmed breast cancer, complete immunohistochemistry data, and proven metastatic axillary lymph nodes were evaluated. The sonomorphological characteristics of these metastatic axillary lymph nodes were subsequently correlated with the molecular subtype of breast cancer. Radiologists performed the ultrasound assessments, while pathologists confirmed histopathological diagnoses. Among all morphological features, only the cortical contour of the lymph node showed an association with the immunohistochemistry subtype of breast cancer, making our study unique in its ability to assess specific features of abnormal lymph nodes in relation to molecular subtypes of the disease. : Our study highlights a positive correlation between abnormal cortical contour and specific molecular subtypes of breast cancer. A concentric pattern predominates in the Luminal A subtype and HER2 neu-enriched subtype; an eccentric pattern is most common in the triple-negative basal-like subtype; and a focal pattern of cortical thickening is notably present in the Luminal B HER2+ subtype.