Progressive multifocal leukoencephalopathy, neuroradiology-neuropathology

ABSTRACT

Introduction: Progressive multifocal leukoencepha-lopathy (PmL) is an unfavorable demyelinating disease of the CNS caused by reactivation of JC virus (JCV). JCV is a double-stranded DNA human polyomavirus predominatingly acquired in childhood. Blood samples taken from healthy persons indicate that 50-90% of adults have been exposed to this virus. JCV is an opportunistic pathogen, with PmL manifesting primarily in patients with immunodefciency or taking immunomodulatory treatments or with lymphoproliferative diseases. We report a patient who developed PmL shortly after diagnosis of follicular lymphomma. Case presentation A 70-year-old-woman admitted to the neurological departament with hemiparesis, psy-chomotor slowing down, balance problems, dizziness and in depressed mood. the patient underwent aorto-femoral transplant 12 years ago and for 10 years was under constant observation of a hematologist due to enlarged lymph nodes. Five years ago, the patient had planoepithelial cell carcinoma removed. the patient also sufered from COViD-19 infection and sufered from depression. elevated leukocytosis and D dimers, were the only abnormal results obtained in laboratory tests. However, pulmonary embolism was excluded in Ct angio. Cytometry of blood showed follicular lymphoma. Radiological fndings mRi and Ct scans showed multiple asymmetrical pathological areas of hyperin-tense signal in t2-dependent images, hypointense in t1-dependent ones and Ct-hypodense regions which extended continuously in control examinations. they were located in the white matter of multiple lobes of both brain hemispheres subcortically and periventric-ullary. the subcortical U-fbers were involed. they did not show contrast enhancement and mass efect. they showed peripheral ring and patchy difusion restriction particularly at their leading edge. in spite of the used steroid therapy the patient's health deteriorated rapidly. the patient died of symptoms of cardio-respiratory failure 1 month after admission to hospital. Neuropathological features the neuropathological examination revealed numerous foci of demyelination in the white matter of the frontal lobe, the parietal lobe in the pons and in the cerebellum. myelin losses were accompanied by damage to oligodendrocytes and proliferation of macrophages. the nuclei of the damaged oligodendrocytes were enlarged and hyperchromatic, and some had a "ground-glass" appearance typical of viral infection. the astrocytes were bizarre with lobulat-ed, hiperchromatic or hypochromatic nuclei and damage of cytoplasmic procesesses (clasmatodendrosis). Conclusion(s) the triad of neuropathological injuries destruction of oligodendrocytes with intranuclear viral inclusions ("ground-glass" appearance), multifocal demyelination and bizarre astrocytes allowed for the diagnosis of late form of classical progressive multifo-cal leukoencephalopathy (cPmL), despite the short time since diagnosis of follicular lymphoma, but with many years of enlargement of the lymph nodes.