Nasal Obstruction in a Patient with Schwannomatosis

Purpose: Describe a rare presentation of a patient with schwannomatosis, highlighting the involvement of the central skull base.

Introduction: Schwannomatosis is the newest recognized form of neurofibromatosis, an extremely rare disease with an estimated prevalence of 1 in 40,000 and an incidence of 0.58 per 1,000,000 people. This disease characteristically presents in the 3rd-6th decade of life with multiple peripheral schwannomas, benign Schwann cell tumors of the peripheral nervous system. Patients with schwannomatosis, typically present with subcutaneous, cranial, and spinal nerve root schwannomas with associated symptoms of muscular atrophy and chronic pain. Schwannomatosis is an increasingly recognized entity, but the least well characterized form of neurofibromatosis.

This case report describes a unique presentation of a patient with schwannomatosis who presented with progressive, benign sinonasal symptomatology, and was found to have a large schwannoma with destruction of the central skull base.

Case: A 77 year old woman with a personal and family history of schwannomatosis who had previously undergone resection of schwannomas of the brachial plexus, spine, and pleura, as well as a papillary thyroid carcinoma, presented with a 2–3 month history of progressive unilateral nasal airway obstruction and intermittent blood-tinged nasal drainage that failed to improve to medical therapy for rhinosinusitis. Nasal endoscopy revealed a large, pulsatile, left sinonasal tumor emanating from the sphenoethmoidal recess. Magnetic resonance imaging (MRI) revealed a destructive, 5.4 cm × 3.6 cm × 2.5 cm, T2-hyperintense sinonasal mass centered in the left posterior nasal cavity with transcavernous involvement, partial carotid encasement, perineural invasion along foramen ovale and extension through the pterygopalatine fossa to the pterygoid musculature (Fig. 1). Biopsy confirmed diagnosis of schwannoma.

Discussion: This case highlights an uncommon presentation of schwannomatosis, the least well characterized form of neurofibromatosis. Though schwannomas of the sinonasal tract and central skull base are rare, the combination a sinonasal schwannoma in the setting of schwannomatosis is an even less common finding. In addition to review of our patient, we herein review the published literature of this unique, but increasingly recognized entity. In this report, we detail the most common clinical presentation and treatment strategies of sinonasal and anterior skull base schwannomatosis. Multidisciplinary management of patients with schwannomatosis is essential, and gross total resection of skull base schwannomas is achievable and effective.

Fig. 1 T1-weighted (a) axial and (b) coronal postcontrast MRI demonstrating destructive, hyperintense sinonasal lesion with left cavernous involvement and partial encasement of left internal carotid artery.

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No conflict of interest has been declared by the author(s).