A 30-year-old HIV-positive man develops progressive focal neurological deficits. MRI shows multiple non-enhancing white matter lesions. CSF PCR is positive for JC virus. Histology of the lesion would show:

• A Ring-enhancing lesions with bradyzoite-containing cysts
• B Perivascular cuffing with plasma cells and lymphocytes
• C Cryptococcal pseudocysts distending the Virchow-Robin spaces
• D Demyelination with enlarged oligodendrocyte nuclei containing 'ground-glass' viral inclusions, bizarre astrocytes, and macrophages ✓

Explanation

Progressive multifocal leukoencephalopathy (PML), caused by JC virus reactivation in immunocompromised patients, shows demyelination with enlarged oligodendrocyte nuclei containing homogeneous 'ground-glass' viral inclusions, bizarre giant astrocytes, and macrophages removing myelin debris. There is no inflammation or enhancement due to absent immune surveillance. Ring-enhancing cysts describe toxoplasmosis; perivascular cuffing is HIV encephalitis; Virchow-Robin space pseudocysts are cryptococcal meningitis.

Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.