Cavernous Sinus Thrombosis Secondary to Sphenoid Sinus Fungal Ball

An 86-year-old female patient presented to the emergency department with an 8-day history of progressively worsening bitemporal headache and 2 days of diplopia. The patient was afebrile and hemodynamically stable. Initial evaluation was significant for right abducens nerve palsy, erythrocyte sedimentation rate of 60 mm/h, and C-reactive protein of 24.2 mg/L. Computed tomography (CT) imaging was significant for heterogeneous opacification of the right sphenoid sinus and possible dehiscence of the lateral sphenoid sinus (Figure 1B). Subsequent magnetic resonance imaging of the head demonstrated complete opacification of the right sphenoid sinus and thrombosis of the adjacent cavernous sinus on magnetic resonance venogram (Figure 1C and D). Subsequent evaluation by otolaryngology showed an occluded right sphenoid os without purulent drainage. The patient was admitted and started on cefepime 2 g intravenously (IV) every 24 hours, metronidazole 500 mg IV every 8 hours, and continuous high-intensity heparin infusion.

Figure 1.

A, Endoscopic image of the right sphenoid sinus after removal of the majority of fungal balls with small residual fungal debris along the right lateral aspect prior to complete removal. Note the lack of mucopurulence or mucosal necrosis. B, Coronal noncontrast computed tomography scan showing classic heterogenous appearance of the fungal ball in the right sphenoid sinus with mixed hyperdensity. C, Coronal T1-weighted gadolinium: hyperintensity of mucosa with central hypointensity within the fungal ball in the right sphenoid. D, Axial T2 magnetic resonance imaging with hypointensity of the right sphenoid fungal ball.

The patient was taken to the operating room the following day for endoscopic bilateral sphenoidotomy. Dense fungal debris was encountered immediately upon entrance of the right sphenoid os (Figure 1A). Tissue was obtained and frozen sectioning demonstrated fungal elements without evidence of angioinvasion; sphenoid mucosa pathology demonstrated no tissue invasion of the fungal elements. Aspergillus fumigatus grew from tissue cultures, while bacterial cultures were negative. Blood cultures were also negative.

The patients was started on voriconazole 200 mg twice daily for suspected fungal cavernous sinus thrombosis (CST). Postoperatively, the patient endorsed improvement of her headache. She was discharged home on warfarin and a 6-week course of voriconazole 200 mg twice daily. Due to concern for possible bacterial superinfection despite negative cultures, the patient was maintained on outpatient IV infusions of cefepime 2 g every 24 hours and oral metronidazole 500 mg every 8 hours for 6 weeks. The patient experienced an uneventful recovery with complete resolution of her abducens nerve palsy. After 3 months of anticoagulation, a magnetic resonance venogram showed resolution of the CST.

Cavernous sinus thrombosis is a rare condition that carries with it the potential for significant morbidity or even death. Timely diagnosis and early initiation of treatment is imperative for prevention of serious complications. Presenting symptoms may include headache, retro-orbital pain, visual deficits, and diplopia. Examination findings often demonstrate deficits of pupillary reflexes, ophthalmoplegia, and paresthesia of the ophthalmic branch of the trigeminal nerve. ¹

Cavernous sinus thrombosis typically occurs as a complication of acute infection of the paranasal sinuses or middle one-third of the face. ¹ Infection spreads via extension to nearby vessels, resulting in a septic mural thrombus. The sphenoid sinus is a common location of primary infection in CST, typically from an acute bacterial sinusitis or from acute invasive fungal sinusitis in an immunocompromised patient. Spread from this site can occur via extension to the emissary veins or by direct extension through the lateral sinus wall. ² The most common pathogen involved in CST is Staphylococcus aureus, whereas fungal pathogens are exceedingly rare. ³

Paranasal sinus fungal balls are formed by a densely arranged mass of fungal hyphal elements; Aspergillus is the most commonly described pathogen. Acute infection and involvement of surrounding structures is an atypical finding in sinus fungus balls. Kim et al found that extrasinonasal infiltration seen in patients with a sinonasal fungus ball is most commonly due to nonfungal infectious or inflammatory processes rather than fungal invasion. ⁴ However, the uncommon potential of fungal balls to transform into invasive fungal disease has been described. ^{4 -7} Few case reports of CST secondary to invasive fungal infection can be found in the literature. ^{8 -10} Another paper reports 2 cases of CST in patients with bacterial superinfection secondary to sphenoid sinus fungus ball. ¹¹

The mainstay of treatment of CST is early surgical intervention with source control of the infection. In cases involving immunocompetent patients without evidence of microbial invasion, the role of adjuvant antifungal and antibacterial therapy is unclear. Dyken et al suggest that surgical drainage of the involved sinus without adjuvant treatment is appropriate. ¹² However, it has been hypothesized that CST in these cases is due to local spread of inflammation secondary to bacterial superinfection. ⁶ This provides the rationale for adjuvant antimicrobial treatment. ^13,14 Anticoagulation is another controversial issue in these cases. There has been no definitive improvement in outcomes in cases of CST treated with anticoagulation. ¹⁵ It is suggested, however, that the benefit of preventing thrombus propagation outweighs the risk of hemorrhage. In this case, we present a patient with findings of CST secondary to a sphenoid sinus fungal ball treated with surgical drainage and antimicrobial and anticoagulation therapy resulting in complete resolution.