Huge brachial plexus schwannoma, masking as a cystic neck mass.

Schwannomas are solitary, benign tumors arising from the nerve sheaths. They are frequently reported in the thorax predominantly in the posterior mediastinum, but are rarely seen to arise from the brachial plexus. Schwannomas are well demarcated lesions with a slow insidious growth. Presented is a case of a large brachial plexus schwannoma, masking as a cystic lesion in the lateral neck. The patient presented with concerns of a cystic mass progressively increasing in size over a period of four years, initially symptomless, but later caused numbness and tingling sensation over his right forearm, tip of right thumb and index finger. Following histological confirmation via fine needle aspiration and magnetic resonance imaging, the patient underwent surgical excision where by the tumor was dissected from its attachment to the nerve sheath. The patient recovered well, and by the third day post operatively, his neurological symptoms resolved completely. Upon follow up in clinic 1-week post-surgery, the scar had healed well, and his numbness or tingling sensation remained in abeyance. This case illustrates that a schwannoma may present insidiously as a cystic lesion and its possible origin may arise from the brachial plexus.