Quadrangular space schwannoma affecting the axillary nerve.

Background: Schwannomas are benign neural tumors originating primarily from Schwann cells associated with cranial and spinal nerves, which are a well-known medical entity. However, their occurrence in the extremities, particularly those involving the axillary nerve, is a rare phenomenon with limited literature documentation.

Case description: We present a case of a 29-year-old male who complained of painful swelling in the posterior shoulder region. Further diagnostic investigations, including ultrasound and magnetic resonance imaging, unveiled the presence of a subdeltoid tumor situated in the quadrangular space, originating from the axillary nerve.

Conclusion: This case report documents our experience in successfully surgically excising this rare benign axillary nerve tumor using an extracapsular approach. Intraoperative neural monitoring was employed to safeguard neural integrity. Our case highlights the importance of a high degree of suspicion, early diagnosis, and meticulous surgical techniques in managing such uncommon nerve sheath tumors while preserving neurological function.