Isolated sphenoid sinus fungal infection in an immunocompetent patient is uncommon and can often mimic skull base malignancy. We present a case report of a 53-year-old lady who was found to have an expansile hyperdense mass lesion in the sphenoid sinus with bony destruction, specks of calcification and extension into the posterior nasal cavity on CT. Contrast enhanced MRI demonstrated T2 hypointense and T1 hyperintense signal in the mass with a thin rim of peripheral enhancement. Diagnosis of clival chordoma with haemorrhage was considered on imaging. Nasal endoscopy showed the mass extending into the right middle meatal region. The patient underwent endoscopic endonasal surgery with planned tumour debulking. Intraoperatively, the paranasal sinuses showed bony destruction with yellowish debris in both maxillary sinuses, ethmoidal sinuses and the sphenoid sinuses. Following debridement of the tissue, the skull base dura was seen with no breach or invasion. The sampled tissue material showed Aspergillus flavus growth on microbiology. The patient was started on antifungals and made a full recovery.
Keyword: Fungal ball, Sphenoid fungal sinusitis, Clival mass, T1 hyperintense signal
