Serial sections from a B-CLL BM biopsy infiltrated with CD5⁺ B-CLL cells (immunoperoxidase staining with different combinations of mAbs).

Clusters of Survivin⁺ cells are observed (A), scattered within a nodule of CD5⁺ malignant B lymphocytes (B). A large proportion of CD3⁺ T lymphocytes is interspersed in the same nodule (magnification A, B, C 200 ×) (C).