A 50-year-old woman notices persistent numbness along the medial aspect of her right arm three weeks after undergoing axillary lymph node dissection for breast cancer. Which structure injured during the dissection explains this finding?
- A Intercostobrachial nerve ✓
- B Thoracodorsal nerve
- C Long thoracic nerve
- D Medial pectoral nerve
Correct answer: A. Intercostobrachial nerve
Explanation
The intercostobrachial nerve is the sensory branch of the second intercostal nerve crossing the axilla to supply the medial upper arm and axillary skin. It is commonly sacrificed or stretched during level I and II axillary clearance, leaving numbness or dysaesthesia over that territory. The long thoracic nerve causes winging of the scapula, the thoracodorsal nerve weakens adduction and internal rotation, and the medial pectoral nerve affects pectoralis function, none of which produce sensory loss.
Reference: Gray's Anatomy for Students, 4th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.