In-depth analysis of the tumor spread to the CNS by multiplex-immunohistochemistry confirmed the B cell lineage of the blast-like tumor cells, the high proliferative activity, the partial expression of CD30, and a scarce bystanding infiltration with some CD4+ and CD8+ lymphocytes, the latter frequently co-expressing the proliferation marker Ki67 (Figure 3K). Here, MKI67 is linked to neoplasm.