The diagnosis was made on microscopic features and positivity with Leucocyte common antigen
Additionally, the RS-like cells also expressed CD45 (leukocyte common antigen
), CD20, PAX-5, CD10, BCL-6, and BCL-2 (Figure 2, D through F).
Immunohistochemical staining for CD45 (leukocyte common antigen
), CD5, Melan-A, S100 protein, desmin, HMB-45, CD35, CD21, CD10, EBV, CD34, glypican 3, podoplanin (D2-40), CD31, c-kit, estrogen receptor, progesterone receptor, smooth muscle antigen, calretinin, and CD1a was negative.
Leukocyte common antigen
(CD45) is often expressed along with various T-cell-specific markers, although null-cell immunophenotype forms also exist in spite of having T-cell genotypes.
CD68, leukocyte common antigen
, and pancytokeratin were negative (Figure 3, B).
(2,13) Even for a common antigen
evaluated in a particular tissue, ER in breast specimens for example, data conflict, with a minimum of 1 hour, (19) 6 hours, (14,17) or 24 hours (6,11) in fixative required for uniform and reproducible immunostaining.
For data analysis, most laboratories use a "gating" system in which predetermined combinations of cellular characteristics, for example, intrinsic light scatter properties combined with level of CD45 (leukocyte common antigen
) expression, are used to define populations of cells that are then characterized with respect to expression of specific antigens.
(16) Other stains like [alpha]-fetoprotein, human chorionic gonadotropin, carcinoembryonic antigen, S100 protein, vimentin, epithelial membrane antigen, leukocyte common antigen
, neuron-specific enolase, and human placental lactogen are not demonstrable in spermatocytic seminoma.
Immunohistochemistry according to the avidin-biotin-peroxidase technique (10) using antibodies against vimentin (monoclonal, 1:400; Dako Corporation, Carpinteria, Calif), leukocyte common antigen
(monoclonal, 1:200; Dako), UCHL-1 (monoclonal, 1:200; Dako), CD3 (monoclonal, 1:200; Dako), CD20 (monoclonal, 1:200; Dako), CD30 (monoclonal, 1:20; Dako), EMA (monoclonal, 1: 10 000; Dako), and S100 protein (polyclonal, 1:200; Dako) was performed on 4-[micro]m-thick sections of paraffin-embedded tissue blocks from both breast and axillary lesions.
The cells stained negatively for desmin, S100 protein, glial fibrillary acidic protein, keratin, epithelial membrane antigen, CAM 5.2, HMB-45, leukocyte common antigen
, factor VIII-associated antigen, c-Kit, and CD34.
Representative sections of the surgical resection specimen were fixed in formalin, embedded in paraffin, and stained with hematoxylin-eosin, as well as immunohistochemically using a diaminobenzidine method, with antibodies directed against S100 protein (used here as a marker for cells of chondrocytic origin), CD45 (leukocyte common antigen
), and CD68 (a macrophage-monocyte marker).
Leukocyte common antigen
(prediluted, Dako) stain demonstrated membranous staining pattern of the histiocytic cells and engulfed lymphocytes.