Fig. 2
Histologic sections from brain biopsy. Hematoxylin and eosin stains at 10 (A) and 40 (B) magnification reveal fragments of brain tissue containing a sparse perivascular lymphocytic infiltrate composed of small cells with mildly irregular nuclei, mature chromatin, inconspicuous nucleoli, and scant cytoplasm. There is no overt tissue destruction or necrosis, and mitotic figures are not identified. CD8 immunostain at 10 (C) and 40 (D) magnification show that perivascular lymphocytes are CD8 positive. Additional immunohistochemical studies confirmed the T-cell phenotype (not shown)