Progressive multifocal leukoencephalopathy (PML)

Case contributed by Maxime St-Amant
Diagnosis almost certain

Presentation

Known HIV+ patient with altered mental state.

Patient Data

Age: 40 years
Gender: Male

Non-specific findings of juxtacortical (subcortical U-fibers) white matter T2/FLAIR hyperintensities involving the precentral gyri at the upper convexity. There are similar hyperintensities in the right thalamic/posterior arm of the internal capsule. 

Case Discussion

These findings are non-specific, but in an HIV+ patient, PML is not excluded. The main differential diagnosis would be HIV encephalitisCMV encephalitis, IRIS (Immune Reconstitution Inflammatory Syndrome), ADEM & multiple sclerosis.

This case is atypical as the findings are not as extensive as expected in PML. The patient died a few months later. This patient had a prior brain biopsy which confirmed JC virus-infected oligodendrocytes with enlarged amphophilic nuclei located at the periphery of the lesions.

Other pathologic findings include :

  • reactive gliosis with enlarged astrocytes
  • macrophages containing phagocytosed cellular debris and myelin​​

How to use cases

You can use Radiopaedia cases in a variety of ways to help you learn and teach.

Creating your own cases is easy.

Updating… Please wait.

 Unable to process the form. Check for errors and try again.

 Thank you for updating your details.