Allergic Fungal Sinusitis Presenting with Bilateral Abducens Nerve Palsy

Abstract

Objective: 1) Report a very unusual presentation of allergic fungal sinusitis. 2) Alert the practicing clinician to consider allergic fungal sinusitis in the differential diagnosis of unilateral or bilateral cranial neuropathies. Method: We report a case from 2010 of a 39-year-old man presenting initially with bilateral abducens nerve palsy and subsequently found to have allergic fungal sinusitis with skull base erosion. The patient underwent an endoscopic approach and resection of the lesion, which extended intracranially into the epidural space. Results: An endoscopic image-guided resection of the skull base lesion was successfully performed in the patient, with intraoperative findings consistent with allergic fungal sinusitis. Pathology and microbiology results revealed aspergillus fumigatus. Postoperatively the patient recovered well with complete resolution of his left abducens nerve function and no CSF leak. AFS, reportedly present in as many as 5%-10% of patients with chronic rhinosinusitis, can present with local destruction and extensive involvement of adjacent critical structures in immunocompetent patients. This is the second known case of fungal sinusitis presenting with bilateral abducens nerve palsy, and the first in an otherwise asymptomatic healthy patient. Conclusion: Allergic fungal sinusitis has repeatedly been demonstrated to cause aggressive local destruction, often out of proportion to patient symptomatology. This case contributes to the literature an exceedingly rare initial presentation of this pathology, alerting the clinician to consider AFS in the differential diagnosis of unilateral or bilateral cranial neuropathies.