Figure 2.

Example of human immunodeficiency virus–positive anal high-grade squamous intraepithelial lesions (HSILs) and corresponding mucosa-infiltrating T lymphocytes. (A), The lesion shows severe cytological atypia and numerous mitoses in the squamous epithelium, consistent with HSILs. Hematoxylin and eosin, original magnification 100×. Scattered CD4⁺ T lymphocytes (red and black arrows) (B) and numerous CD8⁺ T lymphocytes (red and black arrows) (C) are present in the dysplastic epithelium (intraepithelial compartment, red line) and underlying lamina propria (stromal compartment, black line). Immunohistochemistry using antibodies against CD4 and CD8, original magnification 100×.