Anaplastic large cell lymphoma
What is anaplastic large cell lymphoma (ALCL)?
ALCL is a rare type of non-Hodgkin lymphoma. It is made up of either malignant T-cells (type of cells in the immune system), or ‘Null-lymphocytes’ (lack both B or T-cell markers).
The presence of the protein, ‘CD30 antigen’ on the surface of lymphoma cells is the hallmark of the disease. ALCL occurs in two forms: systemic ALCL which can affect all organs in the body and is aggressive; and primary cutaneous ALCL which is confined to the skin and tends to be slow-growing. There are two subtypes: ALK-negative and ALK-positive, depending on whether the lymphoma cells produce a protein called ‘anaplastic large cell kinase’ (ALK). People with ALK-positive ALCL are generally younger and respond better to treatment than those with ALK-negative ALCL.
How does anaplastic large cell lymphoma affect the body?
Systemic ALCL usually presents with painless enlarged lymph nodes in the neck, armpit or groin. Other parts of the body commonly affected include bones, skin, bone marrow, lungs and the liver. Involvement of these organs is seen in approximately 70% of people at diagnosis and indicates advanced disease (stage 3 or 4). Night sweats, fevers and unexplained weight loss may also be present. In 50% of people with systemic ALCL, there will be elevated blood levels of the enzyme lactate dehydrogenase (LDH). Primary cutaneous ALCL usually presents as a solitary skin nodule. In 20% of cases there may be multiple nodules. Involvement of lymph nodes draining the affected region does not usually lead to more widespread disease. The nodules may regress spontaneously, but also tend to recur.
Who does anaplastic large cell lymphoma commonly affect?
Primary cutaneous ALCL presents in older age groups (median age 55 years), and is rare in children. It is 2-3 times more common in men than in women. Systemic ALK-positive ALCL is more likely to affect children and young adults (median age 34), although there is a group who present later in life. People with systemic ALK-negative ALCL present at a later age (median age 58 years). Systemic ALCL is slightly more common in men than in women.
Do we know what causes anaplastic large cell lymphoma?
The causes are unknown. It is not due to infection and cannot be passed on to others.
How is anaplastic large cell lymphoma treated?
Systemic ALCL is treated with the chemotherapy regimen CHOP (cyclophosphamide, doxorubin, vincristine and prednisolone). Other therapies include radiotherapy, stem cell transplants and steroid therapy. People with ALK-positive ALCL generally respond well to chemotherapy. Primary cutaneous ALCL may go into spontaneous remission (the disease goes away without treatment). However this is inevitably followed by a relapse. If no spontaneous remission occurs, or if the lymphoma relapses, the most common treatments for this type of ALCL include radiation therapy and/or surgery to remove the affected area of skin. When there is extensive involvement that cannot be treated with these localised therapies, systemic chemotherapy may be required.