T/NK cell lymphomas

Extranodal NK/T-cell lymphoma, nasal type Enteropathy-type T-cell lymphoma Hepatosplenic gamma-delta T-cell lymphoma Subcutaneous panniculitis-like T-cell lymphoma Mycosis fungoides/sezary syndrome... 

Hairy cell leukemia Extranodal NK/T cell lymphoma, nasal type ... 

The latent membrane protein (LMP-1) is a viral protein that protects infected cells from apoptosis through up-regulation of BCL-2. As such, it serves as a marker of EBV infection. The correlation of LMP-1 by immuno-histochemistry to EBV RNA by in situ hybridization is reportedly good for many diseases but is poor for NK/T cell lymphomas. This may be attributable to the latency state of the virus. 

This pair of granule-associated proteins is also localized to cytotoxic T and NK cells. They are essential for both apoptosis and induced cell death of target cells via induction of perforated cell membranes. However, their expression is assumed to be evidence of an activated state. They mark subcutaneous panniculitis-like T-cell lymphoma, aggressive NK-cell leukemia, and extra-nodal NK/T cell lymphoma, nasal type. 

Type II latency, characterized by the expression of both EBNA-1 and LMPs, usually associated with Hodgkin s lymphoma, lymphoepithelial (nasopharyngeal) carcinoma, peripheral T-cell lymphoma and NK/T-cell lymphoma. 

Ishida T, Inagaki H, Utsunomiya A, et al. CXC chemokine receptor 3 and CC chemokine receptor 4 expression in T-cell and NK-cell lymphomas with special reference to clinicopathological significance for peripheral T-cell lymphoma, unspecified. Clin Cancer Res 2004 10 5494-5500. 

T/NK (natural killer) cell lymphomas are much less common in Western countries and much less understood than the B cell lymphomas. Thus, the discussion of these entities will be much briefer. In addition, a significant number of the T/NK lymphomas, such as enteropathy-type T cell lymphoma, hepatosplenic T cell lymphoma, subcutaneous panniculitis-like T cell lymphoma, blastic NK cell lymphoma, T cell granular lymphocytic leukemia, and adult T cell leukemia/ lymphoma, will not be discussed in this review. The reader is advised to consult the recent World Health Organization Classification of Tumours (J2). 

The T-cell-restricted intracellular antigen (TIA-1) is a cytotoxic granule-associated protein expressed in natural killer (NK) cells and cytotoxic T lymphocytes. It is expressed regardless of the state of activation of the cell. B-cell malignancies are uniformly negative, while NK cell and some T-cell lymphomas have a granular, cytoplasmic positivity. 

CD7 T-ALL and T-cell lymphomas CML, ALL, cholangiocellular carcinoma, pancreas carcinoma Thymocytes, mature T-cells and NK cells, pre-B cells, monocytes, early myeloid cells... 

CDS Mycosis fungoides, subcutaneous panniculitis-like T-cell lymphoma T-cell large granular lymphocytic Leukemia, CLL. mantle cell lymphoma Suppressor/cytotoxic T-cells and NK-cells... 

CD57 (leu 7) Neuroendocrine tumors T-cell lymphoma and pre T-ALL, chordoma, MPNST, germ cell tumors, papillary thyroid carcinoma, thymic carcinoma, germ cell tumors, synovial sarcoma, carcinoid tumors, schwannoma, mesothelioma, astrocytoma and glioblastoma NK-cells, Schwann cells, gastric chief cells, adrenal medulla, pancreatic islets, renal tubular epithelium, epithelial cells of thymic cortex, retina, oligodendrocytes... 

The malignant lymphomas are hematologic cancers that consist of a cluster of diseases of the lymphoid tissue. The primary malignant cells for lymphomas are lymphocytes of B-cell, T-cell, and NK-cell origin. These cells originate from a small population of... 

Petit, B., Leroy, K., Kanavaros, P., Boulland, M., Druet-Cabanac, M., Haioun, C., Bordessoule, D., and Gaulard, P. 2001. Expression ofp53 protein in T and NK-cell lymphomas is associated with some clinicopathologic entities but rarely related to p53 mutations. Human Pathol. 32 196-204. 

These tumors include all T cell neoplasms that are derived from postthymic T cells and, because of immunophenotypic and apparent biologic similarities, include the natural killer (NK) cell lymphomas. 

Approximately 70% of PTCLs exhibit aberrant expression of the pan-T cell antigens. The most frequently lost pan-T cell antigen is CD7, which is absent in approximately 50% of cases, whereas the remaining pan-T cell antigens (CD2, CD3, and CD5) are absent in 10-30% of cases (CIO, D19, P6, P10). Most tumors express CD4, with only small percentage of cases expressing the CD4— CD8+, CD4- CD8-, or CD4+ CD8+ phenotype (D19, P6, P10). In paraffin tissue sections, polyclonal CD3 is a reliable marker of T cells, detecting more than 90% of PTCLs (Cl, CIO, C14, Mil). A variable number of cases express cytotoxic proteins however, the number of positive PTCL cases is less than that of either systemic ALCL or T/NK cell lymphomas (B22, Cll, F8, K14). 

Cll. Chan, A. C., Ho, J. W., Chiang, A. K., and Srivastava, G., Phenotypic and cytotoxic characteristics of peripheral T-cell and NK-cell lymphomas in relation to Epstein-Barr virus association. Histopathology 34, 16-24 (1999). 

Chan AC, Ho JW, Chiang AK, et al. Phenotypic and cytotoxic chatactetistics of petiphetal T-cell and NK-cell lymphomas in telation to Epstein-Batt virus association. Histopathology. 1999 34(l) 16-24. 

CD56 NK-lymphomas, neuroendocrine tumors (small cell carcinoma and carcinoid), pheochromocytoma, neuroblastoma, paraganglioma, Merkel cell tumor Schwannoma, synovial sarcoma, embryonal and alveolarrhabdomyosarcoma, meningioma, melanoma, chordoma, epithelioid sarcoma NK-cells, T-cells, cerebellum and brain cortex, neuromuscular junctions, neuroendocrine tissue, neurons, osteoblasts... 

AID-induced c-myc translocation, miR-155 acts as a tumor suppressor microRNA [335, 336]. The promoter gene of miR-124-1 in chromosome 8p is frequently methylated (silenced) in human malignant lymphoma cells, including those of NK/T lymphoma cells. The miR-124-2 is a direct inhibitor of the CDK6 cyclin-dependent kinase mRNA [337]. Moderate and pronounced anti-AID mRNA activity is exerted by miR-155 and miR-93, respectively [338]. 

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