Contrast-enhancing progressive multifocal leukoencephalopathy: radiological and pathological correlations: case...

Area of Science:

• Neuroscience
• Infectious Diseases
• Radiology

Background:

• Progressive multifocal leukoencephalopathy (PML) is an opportunistic infection caused by the JC papovavirus, typically affecting individuals with compromised cellular immunity.
• While often associated with hematological malignancies, PML is increasingly recognized in other immunocompromised states, notably human immunodeficiency virus (HIV) infection.
• Central nervous system (CNS) manifestations are common in acquired immunodeficiency syndrome (AIDS), with toxoplasmosis and lymphoma being frequent differentials.

Observation:

• A 40-year-old woman with HIV presented with hemiparesis, visual disturbances, and ataxia.
• Magnetic resonance imaging (MRI) revealed a contrast-enhancing lesion in the left middle cerebellar peduncle, causing mild ventricular compression.
• A stereotactic serial biopsy, initially presumed to be glioma, histologically confirmed early PML.

Findings:

• PML lesions can exhibit contrast enhancement following gadolinium administration, an atypical radiographic characteristic.
• This contrasts with the typical presentation of PML, which usually lacks contrast enhancement.
• The presence of contrast enhancement in PML lesions associated with HIV has been documented.

Implications:

• The diagnosis of PML should be considered in HIV-positive patients presenting with contrast-enhancing CNS lesions.
• Atypical imaging findings in PML necessitate a broader differential diagnosis in immunocompromised patients.
• Stereotactic serial biopsy may be required for definitive diagnosis of PML when characteristic radiographic features are absent or atypical.