Chronic Invasive Fungal Sinusitis

Overview:
-Inhaled fungal organisms are deposited in the nasal passageways and paranasal sinuses
-Insidious progression over several months to years in which fungal organisms invade the mucosa, submucosa,
blood vessels, and bony walls of the paranasal sinuses
-Causes significant morbidity and may even be fatal
-Common organisms include Alternaria, Aspergillus, Bipolaris, Candida, Curvularia, Mucor, and Pseudallescheria

Clinical:

-Individuals are usually immunocompetent or have a milder level of immunocompromise
-Frequent history of chronic sinusitis
-Symptoms include paranasal sinus pain, serosanguinous nasal discharge, epistaxis, and fever
-Symptoms may also include headache, lethargy, mental status changes, seizures, neurologic deficits, and
maxillofacial soft tissue swelling when complicated by intracranial or maxillofacial extension
-Characteristic association with the orbital apex syndrome consisting of proptosis, visual disturbances, and
ocular immobility

Imaging:

-Hyperdense soft tissue on non-contrast CT within one or more of the paranasal sinuses
-May be mass-like and mimic a malignancy
-Variable T1 and T2 WI signal intensity but frequently hypointense on T1 WI and very hypointense T2 WI
-Erosion and possibly expansion of the involved sinus
-Invasion of adjacent structures such as the orbit, anterior cranial fossa, and maxillofacial soft tissues
-Obliteration of the periantral fat planes about the maxillary sinus is an indicator of invasive disease
-Associated findings include meningitis, epidural abscess, cerebritis or cerebral abscess, cavernous sinus
thrombosis, osteomyelitis, mycotic aneurysm, cerebral infarct, and orbital infection

Treatment and Prognosis:

-Treatment needs to be as aggressive as for the acute invasive fungal sinusitis
-Treatment includes surgical exenteration of the affected tissues
-Systemic antifungal medication is required
-Frequent recurrence necessitates close surveillance