Six months after a modified radical mastectomy, a patient reports persistent numbness along the medial side of the upper arm and axilla. Which nerve was most likely divided?
- A Medial cutaneous nerve of the forearm
- B Medial pectoral nerve
- C Intercostobrachial nerve ✓
- D Second intercostal nerve anterior ramus to the chest wall
Correct answer: C. Intercostobrachial nerve
Explanation
The intercostobrachial nerve is the lateral cutaneous branch of the second intercostal nerve. It crosses the axilla to supply skin of the medial upper arm and axilla and is commonly sacrificed or stretched during axillary clearance, leaving characteristic numbness. The medial cutaneous nerve of the forearm supplies the forearm below the elbow, which does not fit this distribution.
Reference: Moore's Clinically Oriented Anatomy, 9th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.