A case of allergic fungal rhinosinusitis with extensive skull base bone defects on imaging studies

Abstract

Allergic fungal rhinosinusitis (AFRS) is a highly recurrent and refractory sinusitis with marked eosinophilic infiltration. This report described a case of AFRS, presenting with extensive cranial base bone defects on sinus computed tomography (CT) scan. This disease needs to be differentiated from invasive fungal sinusitis or a malignant sinus tumor. The patient was a 21-year-old male, who developed a severe headache and fever while receiving treatment for chronic sinusitis at another hospital. He visited the emergency department of a general hospital. Physical examination revealed exophthalmos, and the CT scan revealed bone defects in the anterior skull base, right orbital wall, and sphenoid sinus. The patient was, therefore, transported to our department as an emergency case, and subsequently, underwent an endoscopic sinus surgery under general anesthesia. A large fungal mass was found in the right posterior ethmoidal cells and the sphenoid sinus. Defects were also observed in the sphenoid sinus septum and the roof of the right posterior ethmoid sinus. Histopathological examination revealed eosinophilic mucin and fungi. Based on the absence of fungal infiltration into the sinus mucosa, the patient was diagnosed with AFRS. The CT scan showed the characteristic findings of bone remodeling, which are specific for AFRS. The patient was treated effectively with sphenoid sinus singularization and steroid nasal drop therapy in the suspended head position. Postoperative recurrence was not observed, and the patient is being followed up.