Progressive multifocal leukoencephalopathy (PML) is a rare and often fatal neurologic disease that has been known to occur in patients with immunosuppression, due to reactivation of the polyomavirus JC ( JC virus). This severe clinical entity is aggressive, involving the white matter and cortex. Clinical manifestations include motor weakness, gait deformities, visual field deficits, speech disturbances, and behavioral abnormalities. Identifying key histopathologic features of PML via brain biopsy remains the gold standard for diagnosis. However, this poses considerable risk to patients and is not without potential sampling errors and complications. The diagnosis of PML can also be accurately made through identifying a triad of (1) clinical features/symptoms; (2) classic neuroimaging findings such as an increased signal on T2-weighted MRI images with fluid-attenuated inversion recover (FLAIR) sequences, and (3) the presence of JC virus on PCR in CSF studies. Reports in the literature exist on the association of PML in patients treated with immunomodulatory drugs, such as Rituximab. As immunosuppressive therapy is being utilized more frequently, it is important for practitioners to be cognizant of the association between immunosuppressive agents, in particular anti-tumor chemotherapeutic agents and biologics and the development of PML. We aim to present an extremely rare and progressive clinicopathologic entity of PML occurring uniquely as a nonenhancing temporal lesion, which differs from the common frontal and parietal lesions, diagnosed on the basis of using clinical symptomatology, radiographic findings and CSF analysis. We suggest that PML should be included in the differential diagnosis and active work-up in patients with recent Rituximab therapy presenting with unexplained clinical and radiographic changes.
Published on: January 15, 2021
Citation: Woodford A, Conte GA, Sedarous M, Hossain MA. 2020. Progressive Multifocal Leukoencephalopathy Following Treatment with Rituximab in a Patient with Non-Hodgkin’s Lymphoma: Diagnosing a Rare Disease. J Neuroimaging Psychiatry Neurol 5(2): 24-28.