Peter, a 66-year-old male, complained of a persistent headache during a routine follow-up appointment to monitor the immunosuppressive medication he takes for a heart and lung transplant he received 3 years ago. The headache initiated in the occipital region approximately 8 weeks ago, then later shifted to the frontal area. He initially downplayed the severity of the headache, but further questioning showed several worrying signs.
Clinical examination revealed photophobia, left-sided weakness, and occasional tingling sensations in his left upper limb. Neurological assessment indicated mild cognitive impairment and weakness in the left upper limb.
He has also had type 1 diabetes since childhood, but it is generally well-controlled using his insulin pump
|Referred from||Transplant clinic|
|Diagnoses||Diabetes mellitus type 1 (insulin pump); heart-lung transplantation (Cyclosporine 200 mg twice daily)|
Which tests would you order?
Complete Blood Count
Brain Imaging (MRI/CT)
Erythrocyte Sedimentation Rate (ESR) and C-Reactive Protein (CRP)
Lumbar Puncture (LP) and Cerebrospinal Fluid (CSF) Analysis
Polymerase Chain Reaction (PCR) for Fungal DNA
|Blood cultures||Negative for Aspergillus fumigatus.|
|Complete blood count||Elevated white blood cell count, indicative of infection.|
|Imaging||Initial CT scan revealed a single well-defined 12mm lesion with distinct borders within the parenchyma. Midline shift, infarction and ventricular effacement were not observed
MRI showed mixed signal intensity on T1 and T2-weighted images. Post-contrast images reveal peripheral rim enhancement, with surrounding hyperintense areas indicating mild perilesional oedema.
|ESR & CRP||Elevated, consistent with inflammation.|
|CSF analysis||Elevated white blood cell count & increased protein levels
Aspergillus PCR positive
Culture positive for Aspergillus fumigatus
What is his diagnosis?
Cerebral Aspergillus Abscess
Positive fungal cultures and Aspergillus PCR are strong evidence of a fungal cause
Bacterial brain abscess
Furthermore, the absence of typical risk factors for bacterial brain abscess such as sinusitis, dental infections or recent head trauma makes this diagnosis less likely.
Infection should always be suspected for patients receiving immunosuppressive medication
Oedema and inflammation were managed using corticosteroids, particularly dexamethasone. Repeat imaging and CSF cultures were used to monitor response to treatment.
Surgical intervention to drain and biopsy the lesion were discussed as an option in case the abscess failed to respond to medical management
The antimicrobial pharmacist recommended it was safe to step down to oral voriconazole, which allowed him to be discharged home. He will stay on antifungal treatment for at least 6 months and receive regular follow-ups and repeat CT scans