A brain biopsy from an HIV-positive patient with CD4 <50 cells/μL shows enlarged oligodendrocytes with ground-glass nuclei and reactive astrocytes with bizarre nuclear forms (Creutzfeldt cells), no inflammatory infiltrate, and multiple foci of demyelination. This is most consistent with:
- A Cytomegalovirus encephalitis
- B Cryptococcal meningoencephalitis
- C Progressive multifocal leukoencephalopathy (PML) due to JC virus reactivation ✓
- D Toxoplasma gondii encephalitis
Explanation
PML is caused by JC polyomavirus reactivation in immunocompromised patients. The hallmark histology includes: enlarged oligodendrocytes with ground-glass basophilic intranuclear inclusions (JC virus inclusions), markedly enlarged bizarre astrocytes called Creutzfeldt cells (or Creutzfeldt-Alzheimer cells), and multifocal demyelinating lesions affecting white matter without surrounding inflammation (because of severe immunodeficiency). CMV encephalitis shows periventricular involvement with cytomegalic cells and 'owl eye' inclusions. Cryptococcus shows gelatinous pseudocysts. Toxoplasmosis shows ring-enhancing abscesses with bradyzoites.
Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.