LEVEL III (APICAL) LYMPHADENOPATHY

• Group of lymph nodes that are the final step in lymph drainage through the axilla  
• Receive lymph from level II nodes and drain into the subclavian lymphatic trunk and supraclavicular nodes, a path that ultimately leads to the thoracic duct on the left side of the thorax and the right lymphatic duct on the right side
• Metastasis to this level automatically indicates N3 nodal staging (stage IIIC disease) 

Related Radiology Article: Ecanow JS, Abe H, Newstead GM, Ecanow DB, Jeske JM. Axillary staging of breast cancer: what the radiologist should know. Radiographics. 2013 Oct;33(6):1589-612.