During axillary dissection for breast cancer, which structure if injured produces numbness along the medial aspect of the upper arm and axilla?

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

Explanation

The intercostobrachial nerve is the lateral cutaneous branch of the second intercostal nerve and crosses the axilla to supply sensation to the medial upper arm and axillary skin. It is routinely encountered during level I and II dissection, and division causes characteristic medial arm numbness or dysaesthesia. The long thoracic nerve causes winging of the scapula, the thoracodorsal nerve weakens adduction and internal rotation of the shoulder, and the medial pectoral nerve affects pectoralis function.

Reference: Sabiston Textbook of Surgery, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.