An immunocompetent 30-year-old presents with recurrent unilateral nasal obstruction, epistaxis, and a CT showing a heterogeneous expansile mass in the right maxillary sinus with central hyperdensity and peripheral rim enhancement. No bony erosion. The most likely diagnosis is:

• A Chronic invasive fungal sinusitis
• B Allergic fungal rhinosinusitis (AFRS)
• C Squamous cell carcinoma of the maxillary sinus
• D Fungal ball (mycetoma) of the maxillary sinus ✓

Explanation

A fungal ball (mycetoma/Aspergillus sinusitis) typically presents in immunocompetent adults as a unilateral hyperdense mass filling the maxillary sinus on CT, often with central calcification and a thick surrounding mucous membrane — no bony erosion and no allergic mucin. AFRS shows bilateral disease, eosinophilia, and heterogeneous 'double density' allergic mucin. Invasive fungal sinusitis occurs in immunocompromised patients with bony erosion. Fungal ball is treated by simple surgical evacuation via FESS without antifungal therapy.

Reference: Dhingra Diseases of Ear, Nose and Throat, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.