Aspergilloma Mimicking Olfactory Groove Meningioma

Central nervous system aspergillosis is rare with reported mortality rate of 13–50% involving foci in paranasal sinuses and even higher mortality rates (80–100%) in patients of immune-compromised status. Modern day imaging offers an opportunity for early diagnosis, but findings are minimal. A typical finding is that of a space occupying mass lesion with iso-hypointense signal on T1-weighted sequences and extreme hypointense appearance on T2-weighted. This results from the concentration of ferromagnetic substances (iron/zinc/magnesium/manganese) within the lesion. Gadolinium enhancement pattern varies from homogeneous to peripheral ring enhancement. The immune-competent hosts present with homogeneous enhancement while those with immune compromise bear more variable radiological appearance. Due to such radiological appearance, meningioma or tuberculoma is considered in differential earlier than fungal granuloma, if not for the hypointense appearance on T2-weighted sequences which strongly points to fungal granuloma. Through this case report, we attempt to highlight the unusual radiological presentation of the entity.