Detection of active caspase 3, PARP-1/p89, Bcl-2, and PI9 in tumor cells of systemic ALCL.

(A) Biopsy specimen of an ALCL patient with more than 5% active caspase 3–positive tumor cells (brown nuclear staining). (B) Biopsy specimen of the same ALCL patient with more than 5% PARP-1/p89–positive tumor cells (brown nuclear staining). Original magnification for panels A and B is × 200. (C) Biopsy specimen of an ALCL patient with more than 5% active caspase 3–positive tumor cells (brown nuclear staining) in combination with cytoplasmic staining of nuclear debris in cells with a macrophagelike morphology (arrows). (D) Double staining of active caspase 3 (brown) and CD68 (red) in a case of ALCL showing cytoplasmic staining of active caspase 3–positive debris. Apart from 2 CD68-negative cells with large, active caspase 3–positive nuclei, 3 CD68–positive cells are observed with active caspase 3–positive cytoplasmic debris (arrows). (E) Biopsy specimen of an ALCL patient with 50% or more Bcl-2–positive tumor cells (brown cytoplasmic staining). Reactive lymphocytes serve as an internal positive control. (F) Red cytoplasmic staining of PI9 in tumor cells of an ALCL case, with dendritic cells serving as an internal positive control. Original magnification for panels C-F is × 400.