Aspergilloma Mimicking Olfactory Groove Meningioma

Area of Science:

• Neurology
• Infectious Diseases
• Radiology

Background:

• Central nervous system aspergillosis is a rare but severe opportunistic infection, particularly in immunocompromised individuals.
• High mortality rates (13-50% general, 80-100% in immunocompromised) underscore the need for early diagnosis.
• Modern neuroimaging aids diagnosis, though findings can be subtle and mimic other pathologies.

Observation:

• Lesions typically present as space-occupying masses with characteristic iso-hypointense signals on T1-weighted and markedly hypointense signals on T2-weighted MRI sequences.
• The T2 hypointensity is attributed to the accumulation of ferromagnetic substances (iron, zinc, magnesium, manganese) within the fungal granuloma.
• Gadolinium enhancement patterns vary, with homogeneous enhancement in immunocompetent hosts and more variable patterns in immunocompromised patients.

Findings:

• The distinct T2-weighted hypointense signal is crucial for differentiating fungal granulomas from other space-occupying lesions like meningiomas or tuberculomas.
• Radiological appearance can be atypical, especially in immunocompromised patients, potentially delaying diagnosis.
• This case report emphasizes recognizing these specific imaging features to improve diagnostic accuracy.

Implications:

• Early and accurate diagnosis of central nervous system aspergillosis through characteristic MRI findings can lead to timely treatment and improved patient outcomes.
• Understanding the radiological nuances, particularly T2-weighted signal characteristics, is vital for neurologists and radiologists.
• Highlighting unusual presentations aids in refining diagnostic criteria and managing this challenging infection.