Allergic Fungal Sinusitis Imitating an Aggressive Skull Base Lesion in the Setting of Pembrolizumab Immunotherapy.

Inflammatory sinusitis in patients receiving anti-PD-1 therapy may be secondary to T-cell infiltration, a similar pathophysiology as immune-related adverse events, and warrants appreciation by otolaryngologists given our increasing exposure to immunotherapy and its head and neck manifestations.