A 50-year-old woman undergoes modified radical mastectomy with axillary lymph node dissection. At follow-up she reports persistent numbness over the medial aspect of the upper arm and axilla. Which structure was most likely injured?

• A Long thoracic nerve
• B Thoracodorsal nerve
• C Medial pectoral nerve
• D Intercostobrachial nerve ✓

Explanation

The intercostobrachial nerve (lateral cutaneous branch of the second intercostal nerve) traverses the axillary fat and supplies sensation to the medial upper arm and axilla. Sacrifice during axillary clearance causes the classic sensory deficit described. Long thoracic injury causes winged scapula and thoracodorsal injury weakens adduction, neither producing this sensory loss.

Reference: Bailey and Love's Short Practice of Surgery, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.