case_images: PMC8725211_01
case_images: Magnetic resonance imaging findings over time. Upper row: T2-weighted
  axial images show hyperintense white-matter lesions in the cerebellum.
  Middle row: Axial T1 gadolinium (Gd)-weighted images show no
  Gd-enhancement. Lower row: Axial diffusion weighted image shows no
  restricted diffusion.
case_images: 10.1177_11795735211037798-fig1.jpg
case_images: PMC8725211_01_10.1177_11795735211037798-fig1.jpg
case_images: fig1-11795735211037798
case_images: Cranial magnetic resonance imaging (MRI) showed multifocal T2w-hyperintense white-matter lesions without contrast-enhancement, edema, or restricted diffusion predominantly involving the cerebellum (Figure 1). MRI follow-up examination revealed regression of the cerebellar lesions (Figure 1).
case_images: Overview of the patient's history and serum neurofilament light chain
  values. Leukocyte counts are displayed as a blue line. Lymphocyte counts
  are displayed as a violet line. Clinical events (black arrows) are
  indicated. Duration of treatments is depicted with lines of different
  colors on the top of the diagram. Serum neurofilament light chain levels
  are displayed as a red line.
case_images: 10.1177_11795735211037798-fig2.jpg
case_images: PMC8725211_01_10.1177_11795735211037798-fig2.jpg
case_images: fig2-11795735211037798
case_images: During this time, lymphocyte counts were below 500/mm3 in all routine measurements (Figure 2). The clinical history included chronic alcohol and nicotine abuse (Figure 2). Serum neurofilament light chain (sNfL) levels were 149.9 pg/mL at PML diagnosis and constantly declined over the follow-up measurements 1, 2, and 3 months after diagnosis (Figure 2).