Clinical Characteristics and Outcomes of Surgical Resection in Schwannomatosis

Introduction: Schwannomatosis (SWN) is an uncommon neurocutaneous disorder related to the neurocutaneous syndrome neurofibromatosis type 2 and characterized by numerous schwannomas in the absence of bilateral vestibular schwannomas. We aim to investigate the clinical characteristics and neurological outcomes of patients diagnosed with SWN and underwent surgical resection for schwannoma at Johns Hopkins Medical Institutes.

Methods: The medical records were retrospectively reviewed. The clinical outcomes were studied, including pain, sensory deficits, motor weakness, and tumor recurrence at the last available follow-up visit.

Results: A total of 85 patients were included [Mean age, 44.63 (16.20) years; 57% women]. About one-third had a family history of malignancy (35.3%). More than half (56.4%) had schwannomas on peripheral nerves, 27.1% had spinal schwannomas, and 16.5% had brachial plexus schwannomas. Pain was the most common presenting symptom (94.1%), followed by sensory deficits (36.4%) and motor weakness (30.6%). About 36.5% of patients underwent four or more tumor resections. The gross total resection (GTR) was achieved in most patients (87.1%). Postoperatively, with a mean follow-up duration of 68.42 (58.19) months, the proportion of patients with pain decreased to 56.5%, with an 80.0% improvement rate among those with preoperative pain. The proportions of patients with sensory deficits and motor weakness dropped to 32.9% and 28.2%, respectively. Having a high number of resections (≥4) was significantly associated with the pain and weakness outcomes (p=0.008) compared to those with < 4 resections. No significant differences in pain, sensory, or weakness outcomes by the location of the tumor in the spine, brachial plexus, or other peripheral nervous system.

Conclusion : To date, this is one of the largest cohorts of SWN at a single institution. SWN frequently requires multiple surgeries, and motor deficits related to new tumors or surgical interventions are common. Thus, proper patient selection for surgical intervention needs to consider benefits and risks.