Fig. 5

Histopathological stereotactic brain biopsy results. Adjustments of individual color channels were not performed. a tumor cells were diffusely distributed, and the abnormally proliferating lymphocytes were primarily B cells. The cells were large and distributed around blood vessels (H&E, 200 ×). b no expression of the glial fibrillary acidic protein (GFAP) under microscopy (IHC, 200 ×). c strong CD79ɑ expression in Neoplastic B cell membranes (IHC, 200 ×). d BCL-6 expression in the nucleus of neoplastic B cells (IHC, 200 ×). e scattered CD3-positive interspersed T lymphocytes, suggesting no CD3 expression in neoplastic B cells (IHC, 200 ×). f diffuse expression of CD20 in the cell membrane of Neoplastic B cells (IHC, 200 ×). g high proliferation index for and high Ki67 expression in tumor cells; and the percent of Ki67-positive cells in the nucleus was 85% (IHC, 200 ×). h strong PAX5 expression in the nucleus of neoplastic B cells (H&E, 200 ×)