T-cell lymphoma is a general term consisting of four classes of lymphoma that involve T-cells – peripheral T cell lymphoma, cutaneous T cell lymphomas, anaplastic large cell lymphoma and angioimmunoblastic T cell lymphoma. They account for 15% of all non-Hodgkin’s lymphomas (NHL)s.
Cutaneous T-cell lymphoma is a slow growing malignancy of skin-homing T-cells accounting for 2-3% of NHLs. It typically affects adults between 55-60 years. Malignant cells are able to spread to unaffected skin, and can disseminate into the blood and lymph nodes. At early stages, life expectancy is comparable to healthy individuals. Once progressed, life expectancy ranges between 3-9 years. Anaplastic large cell lymphoma accounts for 12-15% of T-cell lymphomas which can be further divided into three types – two systemic fast growing types and one slow growing non-systemic type. It is an aggressive CD30+ NHL and is associated with NPM-ALK translocation. It is more likely to occur in younger patients and has a more favourable prognosis with 70-90% 5-year survival rates.
Angioimmunoblastic lymphoma accounts for 1-2% of NHLs but is the most common subtype of T-cell lymphomas. It is fast growing and thought to be associated with allergic reactions, infections and exposure to drugs. Although two-thirds of patients can achieve complete remission, median survival is 3 years. Peripheral T cell lymphoma refers to the rest of the T-cell lymphomas. Although most patients have disease confined to lymph nodes, the liver, gastrointestinal tract, bone marrow and skin can also be involved. This type of peripheral T-cell lymphoma requires combination chemotherapy promptly due to its aggressive nature.