USEFUL IN DIAGNOSING T-CELL AND NATURAL KILLER CELL LYMPHOMAS. CD3 REACT WITH A SUBSET OF NATURAL KILLER CELLS THAT EXPRESS THE CYTOPLASMIC EPSILON CHAIN OF CD3. IN NORMAL TONSIL, THE T CELLS PREDOMINATE IN THE INTERFOLLICULAR REGIONS. DIAGNOSTICALLY, ANTIBODIES TO CD3 ARE USEFUL IN DEMONSTRATING T-CELL LINEAGE OF MALIGNANT LYMPHOMAS.

CD30 IS USED TO DIAGNOSE HODGKIN LYMPHOMA AND ALSO SOME NON HODGKIN LYMPHOMAS LIKE ANAPLASTIC LARGE CELL LYMPHOMA. CD30 IS A MEMBER OF THE TUMOR NECROSIS FACTOR RECEPTOR (TNF-R) SUPERFAMILY. EXPRESSION OF CD30 CAN ALSO BE SEEN IN EMBRYONAL CARCINOMAS, MALIGNANT MELANOMAS, MESENCHYMAL TUMORS AND ACTIVATED T & B LYMPHOCYTES AND PLASMA CELLS. REED-STERNBERG CELLS OF CLASSICAL HODGKIN LYMPHOMA AS WELL AS THE NEOPLASTIC CELLS OF ANAPLASTIC LARGE CELL LYMPHOMA EXPRESS CD30.

B-CELL LYMPHOMA 2 (BCL-2) IS A KEY PROTEIN REGULATOR OF APOPTOSIS. IT IS VARIABLY HIGHLY EXPRESSED IN HEMATOLOGIC MALIGNANCIES. THIS TEST IS USEFUL IN THE DIFFERENTIAL DIAGNOSIS OF NON HODGKIN LYMPHOMAS.

BCL-6 IS A TRANSCRIPTIONAL REGULATOR GENE WHOSE EXPRESSION IS SEEN IN APPROXIMATELY 68% OF ALK POSITIVE ANAPLASTIC LARGE CELL LYMPHOMAS (ALCL). IT IS ALSO EXPRESSED IN FOLLICULAR LYMPHOMAS, DIFFUSE LARGE B CELL LYMPHOMAS, BURKITT LYMPHOMAS AND MAJORITY OF REED STERNBERG CELLS IN NODULAR LYMPHOCYTE PREDOMINANT HODGKIN LYMPHOMA.

CD10 IS MOST USEFUL IN THE DIAGNOSIS OF B-PRECURSOR ACUTE LYMPHOBLASTIC LEUKEMIA, BURKITT LYMPHOMA AND LYMPHOMAS OF FOLLICLE CELL CENTER ORIGIN LIKE FOLLICULAR LYMPHOMA, A SUBSET OF LARGE B-CELL LYMPHOMAS.

KI-67 IS A NUCLEAR PROTEIN PLAYING A PIVOTAL ROLE IN MAINTAINING CELL PROLIFERATION. KI-67 IS PRESENT IN ALL NON-G0 PHASES OF THE CELL CYCLE. BEGINNING IN THE MID-G1, THE LEVEL INCREASES THROUGH S AND G2 TO REACH A PEAK IN M PHASE. IN THE END OF M PHASE, IT IS RAPIDLY CATABOLIZED. KI-67 HAS BEEN EMPLOYED AS A MARKER OF PROLIFERATION AND HENCE, PROGNOSIS IN NEOPLASMS OF MANY TYPES SUCH AS MALIGNANT LYMPHOMAS, PROSTATIC AND BREAST ADENOCARCINOMAS, ASTROCYTIC NEOPLASMS AND SOFT TISSUE NEOPLASMS. KI-67 IS AN ESTABLISHED PROGNOSTIC BIOMARKER IN BREAST CANCER. IT IS WIDELY USED AS A MARKER OF PROLIFERATION.

CD21 STRONGLY STAINS THE CYTOPLASM AND MEMBRANES OF THE FOLLICULAR DENDRITIC CELLS AND THE MEMBRANES OF A SUBSET OF THE MANTLE ZONE LYMPHOCYTES. FOLLICULAR DENDRITIC CELLS FORM A BASKET-WEAVE MESHWORK IN THE GERMINAL CENTERS OF LYMPHOID FOLLICLES, WHERE THEY PRESENT ANTIGENS TO B CELLS. DIAGNOSTICALLY CD21 MAY BE USEFUL TO SUPPORT A DIAGNOSIS OF FOLLICULAR DENDRITIC CELL SARCOMA OR TO CONFIRM THE PRESENCE OF LYMPHOID FOLLICLES.

CD20 IS NOT EXPRESSED BY MOST NORMAL PLASMA CELLS. IT IS ONE OF THE MOST SPECIFIC B-CELL LINEAGE-ASSOCIATED ANTIGENS USED IN THE DIAGNOSIS OF B-CELL LYMPHOMAS.