Atypical lymphocytosis in CSF at post-CAR time points. (A) Representative example of pre-CAR CSF cytospin preparations (low [100×]- and high-power [500× magnification] views). (B) Representative example of atypical lymphocytosis in CSF cytospin preparations at a post-CAR time point (low- and high-power views). The inset shows an atypical large granular lymphocyte at 1000× magnification. (C) Comparison of CSF lymphocyte count between pre- and post-CAR time points (n = 164; ***P < .0001, Wilcoxon test). (D) CSF lymphocyte counts in a representative subset of SRs (n = 8).