Objective: This article describes the use of sonography for the locoregional staging of breast cancer. Sonography may identify mammographically occult disease within the breast. Sonography of the regional nodal basins, including the axilla, infraclavicular, supraclavicular, and internal mammary regions, can identify nodal metastases, which may upstage disease and have implications for prognosis.
Conclusion: The anatomy of the regional nodal basins and the TNM staging system for breast cancer are reviewed, and the implications of ultrasound-detected disease on clinical management and treatment decisions are discussed.
Keywords: breast cancer; sonography; staging; ultrasound.