Breast lymph drains from the tissue into nodal basins, although individual drainage pathways can vary. For a cancer in the upper outer quadrant, with the skin clear and the opposite breast unaffected, which nodal group is the usual first-echelon drainage site for that tumor?
Select an answer to reveal the explanation.
Short Explanation
For a tumor in the upper outer quadrant, you’d usually expect the level I axillary nodes, lateral to the pectoralis minor, to be the first checkpoint along the drainage route. Drainage can vary, so this is the usual pathway, not the only one.
Full Explanation
For an upper outer quadrant tumor, the usual first-echelon basin is the level I axilla, where the nodes lie lateral to the pectoralis minor. Sentinel lymphatic mapping identifies the draining node or nodes for an individual patient; drainage is not invariably confined to this basin. Internal mammary nodes are an important drainage basin, particularly for medial tumors, but are not the usual first-echelon basin for the upper outer quadrant. Contralateral axillary drainage can occur, including with altered lymphatic pathways, but it is not the usual first-echelon route in this scenario. Supraclavicular nodes are not the usual first-echelon basin for an upper outer quadrant tumor. Confirm the individual drainage pattern when determining sentinel nodes.