Hematology Guide

T-cell lymphoma describes several different types of lymphoid leukaemia which affect T cells.

Types include:
T-cell acute lymphoblastic leukemia
Adult T-cell leukemia

Peripheral blood

The neoplastic lymphocytes seen in this disease are large in size with azurophilic granules that contains proteins involved in cell lysis such as perforin and granzyme B.[11]

The requisite lymphocytosis of this disease is typically 2-20×109/L.[7] Immunoglobulin derangements including hypergammaglobulinemia, autoantibodies, and circulating immune complexes are commonly seen.[8][9][10][5]

Etiology

The postulated cells of origin are a transformed CD8+ T-cell with clonal rearrangements of β chain T-cell receptor genes for the majority of cases and a CD8- T-cell with clonal rearrangements of γ chain T-cell receptor genes for a minority of cases.[1]

T-cell large granular lymphocyte leukemia is a disease that exhibits an unexplained, chronic (> 6 months) elevation in large granular lymphocytes (LGLs) in the peripheral blood.[1]

It is also known by the following terms: Proliferation of large granular lymphocytes (LGLs), LGL leukemia, Tγ-lymphoproliferative disorder, T-cell chronic lymphocytic leukemia[1]

T-ALL is believed to be caused by a defect in the Notch signaling pathway.

Normal B cells and T cells can be recognized by laboratory tests that identify distinctive chemicals on their surfaces. Some chemical substances are found only on B cells, and others are found only on T cells.

T cells help protect us against foreign substances (those not normally present in the body). They recognize specific chemicals, such as those found on the outside of virus-infected cells. They then destroy these cells by releasing substances that cause them to develop holes and become leaky. T cells can also release substances called cytokines that attract other types of white blood cells, such as macrophages, which then surround and digest the infected cells.

Precursor B acute lymphoblastic leukemia/lymphoma is a form of lymphoid leukemia.

It consists of the following subtypes:[1]
t(9;22)-BCR/ ABL
t(v;11q23)-MLL rearrangement
t(1;19)-E2A/PBX1
t(12;21)-ETV/ CBFα

Treatment of plasma cell leukemia is by supportive care and systemic chemotherapy. Combination of cyclophosphamide, doxorubicin, vincristine, and prednisone (or dexamethasone) can be used. A second combination is the use of cyclophosphamide, dexamethasone, and thalidomide as for myeloma. Another regimen termed VMCP/VBAP uses alternating vincristine, melphalan (M), cyclophosphamide, prednisone/vincristine, carmustine, doxorubicin, and prednisone polychemotherapy. In general, comination chemotherapy has resulted in median survivals of 18 to 20 months compared to 2 to 6 months when single agent therapy is used. There are anecdotal reports of excellent responses and 2- to 3-year disease-free survivals after autologous stem cell transplantation. Although the clinical and laboratory features of primary and secondary PCL are similar, the response to therapy and overall survival in primary and secondary PCL go from poor to worse. Patients with secondary PCL are usually refractory to chemotherapy and have a poor survival compared with duration (median <2 months).