(A1119) Idiopathic Isolated Fungal Ball Within a Destructive Frontal Mucocele

Introduction: Frontal sinus mucocele is the most common type of spontaneous mucocele. However, fungal balls in the frontal sinus are rare, accounting for only 2% of all reported cases of fungal rhinosinusitis. The occurrence of fungal balls within a frontal sinus mucocele is even more uncommon. We present a case of a 69-year-old male with no history of nasal surgery or trauma, who was found to have a large, destructive frontal sinus mucocele containing fungal balls.

Methods: Retrospective case in a tertiary medical center.

Results: Initially, the patient visited an ophthalmologist due to progressive diplopia, bulging of the right eye, and pressure at the frontal region. Computed tomography revealed an expansile mass causing downward compression of the orbital cavity and bony remodeling of the frontal sinus. The patient subsequently underwent endoscopic sinus surgery with a navigation system. During surgery, fungal debris was identified in the ethmoid sinus, and the frontal recess was found to be completely obstructed and sealed with thick bone. A burr was used to remove the bony portion, allowing the mucocele to be opened. A large amount of brown, clay-like material, consistent with fungal debris, was discovered within the mucocele. The fungal material and mucous secretions were removed, and the inferior outlet of the frontal sinus was sufficiently widened to ensure long-term patency. Histopathological examination was consistent with fungal ball. Following the operation, the patient experienced significant improvement in diplopia and eye position.

Conclusions: Frontal sinus fungal ball within a mucocele is extremely rare, with surgery being the only treatment. This case is unique not only for its rarity but also for the complete isolation of the mucocele by thick bone, creating an independent space. The pathophysiology likely involves fungal balls originating in the frontal and ethmoid sinuses, leading to recurrent infections, severe osteitis, sinus ostium obstruction, and eventually the formation of an isolated mucocele. This is the first reported case of a fungal ball within a frontal mucocele presenting in this manner.