CNS aspergilloma mimicking tumors: Review of CNS aspergillus infection imaging characteristics in the immunocompetent population.

BACKGROUND AND PURPOSE: CNS Aspergillosis is very rare and difficult to diagnose clinically and on imaging. Our objective was to elucidate distinct neuroimaging pattern of CNS aspergillosis in the immunocompetent population that helps to differentiate from other differential diagnosis.

METHODS: Retrospective analysis of brain imaging findings was performed in eight proven cases of central nervous system aspergillosis in immunocompetent patients. Immunocompetent status was screened with clinical and radiological information. Cases were evaluated for anatomical distribution, T1 and T2 signal pattern in MRI and attenuation characteristics in CT scan, post-contrast enhancement pattern, internal inhomogeneity, vascular involvement, calvarial involvement and concomitant paranasal, cavernous sinus or orbital extension. All patients were operated and diagnosis was confirmed on histopathology.

RESULTS: The age range was 19-50 years with mean age of 33.7 years. Concomitant sinonasal disease was seen in six patients (75%). Three patients had orbital extensions. Most of the lesions (n=7) were profoundly hypointense in T2-weighted imaging. The most common enhancement pattern was bright, solid and homogenous enhancement (n=7). Cavernous extension with ICA encasement was always associated with paranasal sinus disease. Six patients showed demineralization or complete resorption of involved bone. All of the fungal masses appear hyperdense on available CT scan images.

CONCLUSION: CNS aspergillus infection in immunocompetent patients has distinct imaging features as compared to CNS aspergillosis in immunocompromised patients. A high index of suspicion in proper clinical settings, even with immunocompetent status and typical imaging features allow us to diagnose CNS aspergillosis in such patients.