Multiple Schwannomas of the Median Nerve: A Case Report and Review of the Literature

INTRODUCTION: Schwannomas are rare benign tumors affecting the peripheral nerves. They can grow in clusters when associated with neurofibromatosis Type II or with schwannomatosis. Typically, patients present with a palpable painless mass. However, some patients, on the other hand, present with symptomatic lesions that resemble a focal nerve compression caused by the encapsulating nature of these tumors. Surgical excision is an excellent solution for solitary symptomatic lesions. However, multiple schwannomas affecting the same nerve add another level of complexity to the surgery since these secondary masses can be too small to be detected on physical examination. A high index of suspension for schwannomatosis complemented with magnetic resonance imaging (MRI) ensures a more efficient pre-operative workup that can save the patient potentially an additional visit to the operating room. CASE REPORT: This is a case of a 36-year-old right-handed female presented to our clinic with a several-years history of a painful mass in her forearm. On physical examination, she had a palpable painful mass that was Tinel positive with pain and paresthesia radiating distally over the median nerve distribution. A subsequent MRI scan showed a second smaller mass distally adjacent to the main lesion along with the median nerve, both appearing to be schwannomas of the median nerve. In this case report, we discuss the patient presentation, diagnostic workup and radiographic finding, surgical technique, and pathological findings in addition to a review of the literature regarding multiple schwannomas affecting the upper extremity. CONCLUSION: Schwannomas are rare benign tumors affecting the peripheral nerves. Despite their solitary nature, a handful of cases are reported in the literature that describes multiple masses encapsulating the same nerve. MRI is utilized to allow proper pre-operative planning and more accurate localization of these tumors to avoid an unplanned return to the operating room.