Which of the following correctly matches the lymphatic drainage of the breast quadrant to its primary nodal group?

• A Medial quadrants → internal mammary (parasternal) nodes; lateral quadrants → axillary nodes ✓
• B All quadrants → exclusively axillary nodes
• C Upper outer quadrant → supraclavicular nodes directly
• D Lower quadrants → external iliac nodes via rectus abdominis route

Explanation

The lateral breast quadrants (especially the upper outer quadrant, which accounts for ~60% of breast cancers) drain predominantly to axillary nodes (Level I–III, anterior/pectoral group). The medial quadrants drain to the internal mammary (parasternal) nodes along the internal thoracic vessels. Some cross-drainage to contralateral breast and subphrenic lymphatics also exists. Knowledge of the dual drainage pathway is essential because internal mammary node involvement changes staging and radiotherapy planning in breast cancer management.

Reference: BD Chaurasia's Human Anatomy, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.