While there are many subtypes of T-cell lymphomas, they are all fairly rare, as a group making up about 10 percent of non-Hodgkin’s lymphomas (NHLs) in the United States.
The T-cell subtypes of NHL include:
- Peripheral T-cell lymphoma, which includes several additional subtypes
- Aggressive NK/T-cell leukemia/lymphoma
Lymphoblastic lymphoma/leukemia can be considered either lymphoma or leukemia, depending on how much of the bone marrow is involved. It involves precursor, not mature, T-cells and is biologically related to and treated like acute lymphocytic leukemia.
Most T-cell NHLs are treated with combination chemotherapy or multi-drug regimens. Patients with some subtypes of T-cell lymphoma may be offered stem cell transplant after their initial therapy and first remission. Most patients who relapse are candidates for stem cell transplant with curative intent. In addition, there are many treatments under investigation in clinical studies. Some treatments target specific subtypes of T-cell lymphomas. Patients can benefit from consulting T-cell experts at academic centers of excellence to discuss treatment options for their specific disease.
Peripheral T-cell lymphoma (PTCL) refers to a diverse group of rare, typically aggressive (fast-growing) T-cell lymphomas that make up the majority of T-cell NHLs in the United States. PTCL arises in the lymph tissue outside of the bone marrow, such as in the lymph nodes, spleen, gastrointestinal tract, and skin.
PTCLs are further subdivided based on distinct clinical or pathological patterns.
Peripheral T-Cell Lymphoma, Not Otherwise Specified
This name is given to T-cell lymphomas that don't readily fit into any of the other subtypes of PTCL. This is the most common subtype, accounting for 25 percent of all PTCLs. As a group, these lymphomas tend to be widespread and aggressive. Most people diagnosed with this disease are in their 60s. Most patients are treated with aggressive chemotherapy shortly after diagnosis.
Angioimmunoblastic T-Cell Lymphoma
Like many of the other subtypes of T-cell lymphomas, this subtype is rare. It makes up about 18 percent of PTCLs. Angioimmunoblastic T-cell lymphoma (AITL) is considered an aggressive subtype and is typically diagnosed at stage III or IV.
People with AITL usually have fever, night sweats, weight loss, skin rashes, and autoimmune disorders, and they often develop infections. While the cause is unknown, AITL has been linked to Epstein-Barr virus, which causes mononucleosis.
Initially this disease may be treated with steroids; however, the disease often progresses, and in addition to the typical treatments for patients with T-cell NHLs, AITL patients may also be treated with radiation therapy for symptom relief.
Anaplastic Large Cell Lymphoma
This is a rare, aggressive type of T-cell lymphoma. It is more common in children, accounting for up to 30 percent of all childhood lymphoma cases. It accounts for about 14 percent of PTCLs in adults.
There are three types of anaplastic large cell lymphoma (ALCL):
- Primary cutaneous ALCL
- ALK-positive (ALK+) ALCL
- ALK-negative (ALK-) ALCL
Primary cutaneous ALCL is one of several types of cutaneous lymphoma, which is often referred to as lymphoma of the skin.
The other two types of ALCL are systemic (throughout the body) and are classified by whether a protein called anaplastic lymphoma kinase (ALK) is expressed. ALK+ ALCL (which expresses the ALK protein) usually affects children, while ALK- ALCL (which does not express the ALK protein) is typically found in adults over age 60. Both ALK+ and ALK- ALCL are treated as aggressive lymphomas. Patients with ALK+ ALCL tend to have excellent outcomes with the standard multi-agent chemotherapy known as CHOP—cyclophosphamide (Cytoxan, Clafen, Neosar), doxorubicin hydrochloride (Adriamycin), vincristine (Oncovin, Vincasar, Vincrex), and prednisone. In 2011, the new drug brentuximab vedotin (Adcetris) was approved for patients with both ALK+ and ALK- relapsed or refractory systemic ALCL.
Extranodal NK/T-Cell Lymphoma, Nasal Type
This subtype, which accounts for 10 percent of all PTCLs, is more common in parts of Asia and South America and is associated with Epstein-Barr virus. It often involves the upper airway passages, such as the nose and upper throat, but it can also invade the skin and digestive tract. In contrast with other PTCLs, this is the only subtype for which radiation is the primary therapy.
Enteropathy-Type T-Cell Lymphoma
This extremely rare subtype is a primary intestinal lymphoma that occurs predominantly in middle-aged men with sensitivity to gluten, the main protein in wheat flour. It develops when the disease gluten-sensitive enteropathy (celiac sprue) progresses to cancer. A gluten-free diet might prevent this lymphoma.
Because of the side effects associated with treatment for this subtype, patients should be treated at an academic center by a doctor who has experience treating this specific disease.
Hepatosplenic T-Cell Lymphoma
People with this extremely rare, aggressive disease, which starts in the liver or spleen, experience fever, abdominal pain, weakness, and swelling of the liver and spleen. This subtype is mainly seen in children and young men and in people with chronic immune-system suppression, usually due to an organ transplant. There is no standard treatment for the disease. Anthracycline-based chemotherapy is associated with satisfactory short-term responses in a majority of patients, but complete remissions are rare. Typically allogeneic stem cell transplant is recommended for patients during their first remission.
Subcutaneous Panniculitis-Like T-Cell Lymphoma
People with this rare, aggressive disease usually have subcutaneous nodules (small bumps or lesions under the skin) on their body, arms, and legs. This disease is typically seen in people from ages 30 to 50, and it is slightly more common in women than men. It is sometimes associated with lupus. It is typically treated with combination chemotherapy.
This aggressive, difficult-to-treat disease affects the natural killer (NK) cells of the immune system. NK-cells are a type of lymphocyte (a white blood cell) that attacks and destroys viruses and tumor cells. People with this subtype have skin lesions similar to those associated with leukemia, cutaneous lymphomas, and other skin diseases. The disease is rare in the United States but is more common in Asia and parts of Latin America. It usually affects older adults and is associated with Epstein-Barr virus. Because of the severity of this disease, patients should be treated at an academic center that can transition them to a stem cell transplant.