Computed tomographic findings in patients with invasive fungal sinusitis

Objective: To determine the radiographic findings of computed tomographic (CT) imaging most suggestive of invasive fungal sinusitis (IFS) in an immunocompromised patient population. Design: A retrospective review of patients with a diagnosis of IFS reached with CT and confirmed by histopathologic evaluation. Setting: An academic tertiary care hospital. Patients: Twenty-three immunocompromised patients with confirmed IFS and preoperative CT imaging. Controls were 10 patients with acute myelocytic leukemia and CT evidence of sinusitis but no history of IFS. Outcome Measures: The CT scans were reviewed to identify factors predictive of invasive fungal disease. Parameters evaluated were nasal cavity and sinus soft tissue thickening, the presence of air-fluid levels, bone erosion, extrasinus extension, and unilateral or bilateral nasal cavity and sinus involvement. Results: The CT findings included severe soft tissue edema of the nasal cavity mucosa (turbinates, lateral nasal wall and floor, and septum) in 21 of the 23 patients, sinus mucoperiosteal thickening in 21, bone erosion in 8, orbital invasion in 6, facial soft tissue swelling in 5, and retroantral fat pad thickening in 2. Two patients had air-fluid levels. No patients had intracranial. involvement. Unilateral involvement was found in 21 patients, and bilateral involvement in 2. Review of the control group revealed only mild soft tissue edema of the nasal cavity in 2 (P<.001), unilateral involvement in 2 (P<.001), and evidence of bone erosion or extrasinus soft tissue involvement in none. Conclusions: Most patients do not have classic CT findings of bone erosion or extrasinus extension in the early course of IFS. We found that severe unilateral thickening of the nasal cavity mucosa was the most consistent finding on CT suggestive of underlying IFS, occurring much more frequently in immunocompromised. patients with IFS than without IFS. Even though severe nasal cavity soft tissue thickening is much more common in IFS, this is a nonspecific finding that can be seen, to a lesser degree, in all forms of rhinosinusitis. Therefore, the clinician cannot rely solely on CT imaging and must maintain a high index of suspicion when evaluating immunocompromised patients to establish a prompt diagnosis. Early nasal endoscopy with biopsy and initiation of appropriate therapy are necessary to improve prognosis.