Adult T cell lymphoma refers to a very rare lymphoid cancer subtype known more specifically as adult T cell leukemia/lymphoma, or ATLL. It is considered a peripheral T cell lymphoma (PTCL).
ATLL (sometimes written as ATL) has four known subtypes: acute, lymphoma, chronic, and smoldering. Prognosis for patients with the chronic or smoldering subtypes is considered to be rather good, but for the acute and lymphoma subtypes, adult T cell lymphoma is a highly aggressive cancer with an extremely poor prognosis—the average time from diagnosis to death is generally under one year. The disease is extraordinarily rare in the US; rather, it is more commonly reported in Japan and other parts of Asia.
The reason the adult T cell lymphoma is called a leukemia/lymphoma is because it is characterized by the build-up of leukemic T cells in the body but it also presents with generalized lymphadenopathy
There are not too many studies that support specific treatment options for those with adult T cell lymphoma. What has been determined is that an autologous stem cell transplantation, preceded by high-dose chemotherapy, is not effective, but that an allogenic transplant may indeed offer about 40% of patients some hope. Otherwise, Zidovudine/IFN-alpha therapy has shown some efficacy in poor prognosis patients, but the treatment for Adult T cell lymphoma has yet to be proven on a large scale.
ATLL is one of the few cancers the cause of which has been almost undeniably linked to a virus, namely the Human T cell Lymphotrophic Virus-1 (HTLV-1). HTLV-1 is the first retrovirus ever to be discovered, and its discovery would be followed closely by the discovery of a few more, including the much-better-known retrovirus, human immunodeficiency virus, or HIV, in 1983.
HTLV-1 is believed to have infected as many as 15-20 million people worldwide, although estimates suggest that only about 500,000 of them will develop human T cell leukemia/lymphoma. That said, many others who are infected with the virus will develop other clinically problematic disorders, ranging from myelopathy to dermatitis to other inflammatory diseases, according to Ewa Maria Szczypinksa, MD, writing for Medscape.
Actual infection by the HTLV-1 virus generally does not get reported because the virus remains latent and doesn't cause any of its own specific adult T cell lymphoma symptoms.
Murphy EL, Hanchard B, Figueroa JP, et al. Modeling the risk of adult T-cell leukemia/lymphoma in persons infected with human T-lymphotropic virus type I. Int/ Cancer. 1989;43:250-253.
Ewa Maria Szczypinksa, MD: Human T-Cell Lymphotrophic Viruses
Tanosaki R, Tobinai K. Adult T-cell Leukemia–Lymphoma: Current Treatment Strategies and Novel Immunological Approaches. Expert Rev Hematol. 2010;3(6):743-753