INTRODUCTION: Aspergillus species are ubiquitous soil fungi. Primary sites of infection are the lungs and paranasal sinuses. Cerebral dissemination arises from continued invasion from sinuses or by hematogenous spread. Invasive aspergillosis is a cause of significant morbidity and mortality in severely immunocompromised hosts. Only a few reports of invasive disease limited to one organ in immunocompetent patients have been published. We are reporting a case of invasive, disseminated aspergillus involving the brain and lungs in an immunocompetent patient.
CASE PRESENTATION: A 31-year-old male presented to the emergency department with new onset generalized seizure. His medical history was significant only for testicular torsion. He had no history of tuberculosis, childhood infections, immunosuppressant therapy, or diabetes. He worked in housing demolition, and was a smoker. On presentation he was afebrile. Physical exam revealed right hemiparesis, right facial droop, dysarthria, and difficulty with word finding. White blood cells were slightly elevated at 12.7 K/uL with 86% neutrophils. Serum glucose was 102 mg/dL. Head Computed Tomography (CT) revealed a left frontal mass with vasogenic edema. Sinuses were normal. Phenytoin and intravenous steroids were started. Pre-craniotomy routine chest X-ray revealed right upper and lower lobe masses. CT thorax demonstrated bilateral upper lobe masses with spiculated margins without lymphadenopathy. Transbronchial biopsies and bronchioalveolar lavage were negative for malignancy. He was started on empiric broad-spectrum antibiotics. Vasculitis serologic studies were all within normal limits. Human immunodeficiency virus, hepatitis serology, and tuberculin test were negative. Cerebral magnetic resonance imaging ten days later revealed growth of the left frontal lesion with central necrosis and a subinsular lesion with leptominingeal enhancement. He underwent craniotomy and a well encapusulated centrally necrotic lesion with frank pus was excised. CT guided biopsy of right lung lesion was performed. Brain and lung histopathology revealed granulomas with eosinophilic infiltrate and necrosis. Immunostains and tissue cultures were positive for Aspergillus fumigatus. He was started on intravenous voriconazole and anidulafungin for two weeks and steroids were weaned. He was discharged on oral voriconazole 300mg twice daily for six months. At one month follow up his only neurologic deficit was subtle expressive aphasia.
DISCUSSIONS: Invasive aspergillosis is the most invasive fungal infection worldwide, and dissemination is a life threatening, fulminant disease. Profound neutropenia is the most common risk factor for disseminated aspergillosis. Those with hematologic malignancies, organ transplants, immunodeficiency (congenital and acquired), on chronic steroid therapy, or with diabetes are also at risk for disseminated disease. Invasive aspergillosis can be seen in immunocompetent patients with pre-existing lung disease such as advanced emphysema with bullae or previous cavity secondary to tuberculosis, neoplasm, or bronchial cyst. Neuroaspergillosis is rare even in severely immunocompromised hosts, with mortality approaching 100% despite prolonged antifungal therapy. Voriconazole has been shown to be more effective than amphotericin-B in the treatment of Neuroaspergillosis due to excellent concentration in the CSF. Extensive investigation revealed no evidence of immunocompromisation. Disseminated neuroaspergillosis with concomitant lung invasion in an immunocompetent host has not been previously reported. An inhaled inoculum from his work environment was the likely route of pulmonary infection with hematogenous spread causing dissemination to the brain, as no evidence for sinus disease was found.
CONCLUSION: Disseminated invasive aspergillosis is exceedlingly rare in immunocompetent hosts. The diagnosis is challenging as malignancy and vasculitis have a similar presentation. A high index of suspicion is needed in whom these diagnoses have been excluded. Treatment of disseminated aspergillosis is prolonged, and CNS involvement portends a grave prognosis if neurosurgical intervention and aggressive antifungal therapy are not instituted early.
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