A 40-year-old woman develops drooping of the right shoulder, lateral displacement of the scapula and weakness of overhead abduction after an excision biopsy of a right posterior cervical lymph node. Which nerve was injured?

• A Long thoracic nerve
• B Spinal accessory nerve ✓
• C Dorsal scapular nerve
• D Suprascapular nerve

Explanation

The spinal accessory nerve crosses the posterior triangle of the neck lying on levator scapulae and is at risk during cervical lymph node biopsy. Injury paralyses trapezius, giving shoulder droop, lateral scapular displacement and impaired abduction above 90 degrees because the scapula cannot rotate upward. Long thoracic nerve injury gives medial winging with serratus anterior weakness, and suprascapular nerve injury weakens supraspinatus and infraspinatus without altering scapular position at rest.

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.