Primary intracerebral aspergillosis in an immunocompetent patient with no risk factors or clear cause: a case report.

Introduction: Intracranial aspergillosis (ICA) is an uncommon, life-threatening central nervous system infection that is caused by the Aspergillus species. Usually, ICA happens in immunocompromised patients. However, it can sometimes happen in immunocompetent patients, which poses a unique diagnostic and therapeutic challenge. Here we present a rare case of primary ICA in an immunocompetent patient. Presentation: A 60-year-old woman presented with aphasia, blurry vision, nausea, and vomiting in addition to a 1-month history of eye pain and decreased vision. Examination showed disorientation, gait apraxia, and sphincter dysfunction. A head computed tomography scan showed several hypodense infarction-like lesions, and on magnetic resonance imaging these lesions appeared to be endemic in nature mimicking metastatic lesions. Therefore, a biopsy was taken and subsequent pathological and immunohistochemical examination confirmed the diagnosis of aspergillosis. Discussion: ICA usually occurs in immunocompromised patients. Nevertheless, it can sometimes happen in immunocompetent patients, and the exact etiology of ICA in immunocompetent patients remains unknown. ICA poses a great diagnostic challenge due to the multiple differential diagnoses that can mimic this condition. Due to this, pathological examination and subsequent IHC staining play a crucial role in diagnosing this condition and differentiating it from other possible diagnoses. Finally, ICA can be treated using antifungal medication and/or surgical resection. However, the prognosis remains poor. Conclusion: Physicians should keep ICA in mind as it can mimic intracranial lesions (such as metastasis and intracranial tuberculosis), which could be differentiated by either performing a pathological examination on a biopsy or by cerebrospinal fluid polymerase chain reaction tests.