Anaplastic Large Cell Lymphoma (ALCL) is a relatively uncommon type of non-Hodgkin’s lymphoma (NHL) that arises from T-cells. T-cells are a type of immune cells that protect the body from infections.
There are two types of anaplastic large cell lymphoma –- the systemic type (that affects lymph nodes and other organs), and the cutaneous type (that affects mainly the skin).
Anaplastic Large Cell Lymphoma – Primary Systemic Type
The systemic type of ALCL affects both children and adults. In adults, it is a relatively rare lymphoma, but in children ALCL accounts for 1 in 10 cases of all lymphomas.
Most individuals with this lymphoma first complain of enlarged lymph nodes, though it rarely affects the intestines or the bone without involving lymph nodes.
Diagnosis is made with a biopsy from the lymph nodes or affected organs -- that shows the special ‘anaplastic’ pattern of this lymphoma under the microscope. The pathologist will often test the biopsy tissue with special lymphoma markers that can identify a unique molecule called CD30 on the surface of the cancer cells in ALCL. The presence of this CD30 molecule sets it apart from other types of NHL.
Another marker test for a special protein, called the ALK protein, is also carried out. Not all individuals with ALCL are positive for ALK. Those who have the ALK protein fare better after treatment than those who don’t. Children are more likely to have the ALK protein than adults.
Once the diagnosis of ALCL is confirmed, a series of tests are carried out to find the lymphoma stage.
Systemic ALCL is treated with chemotherapy. Treatment results are generally good, especially for those who are ALK positive. Rituximab, a monoclonal antibody, used in most of the common forms of NHL is not used in ALCL because it does not work for T-cell lymphomas. A different monoclonal antibody treatment, directed against the CD30 molecule present in ALCL cells, is being tested in clinical trials for those who have disease remaining after treatment or in whom the disease has come back after prior successful treatment.
Anaplastic Large Cell Lymphoma – Primary Cutaneous Type
The cutaneous type of ALCL affects mainly the skin. It is the second most common type of non-Hodgkin’s lymphoma that affects the skin – after cutaneous T-cell lymphoma (CTCL). ALCL of the skin is still a rare condition, mainly affecting older adults.
Affected individuals first notice swellings or ulcers on the skin. A visit to the doctor usually results in a skin biopsy, which confirms the diagnosis. Marker studies for a special molecule CD30 is required to label the disease as ALCL.
About 1 in 4 individuals with ALCL of the skin have affected lymph nodes close to the skin nodules or ulcers. Tests may be done to rule out lymphoma in the chest and abdomen. A bone marrow test may be done as a part of routine investigations.
ALCL of the skin has an excellent prognosis. It is a slow-growing disease that is rarely life-threatening. In some patients, it may even disappear without any treatment. For those with skin lesions limited to a small area, radiation therapy is the treatment of choice. Those with a extensive skin involvement may be treated with low doses of a drug called methotrexate, in the form of oral tablets or injections.