Chronic Invasive Fungal Sinusitis Concerning for Sinonasal Malignancy With Unique Intracranial Extension

Chronic invasive fungal sinusitis is a rare sinonasal pathology characterized by histopathological evidence of fungi causing chronic inflammation, as well as radiologic imaging of bony destruction and extrasinus invasion. Here, the authors have described a case of chronic invasive fungal sinusitis with the presence of a fungal mass, orbital involvement, and intracranial extension into the anterior skull base. Management involved nasal endoscopy with biopsy, postoperative debridement, and antifungal therapy.