Adult T-cell leukaemia/lymphoma (ATLL)

This information page is about adult T-cell leukaemia/lymphoma, a rare type of T-cell lymphoma associated with the HTLV-1 virus.

On this page

What is ATLL and who gets it?

Relapsed and refractory ATLL
Research and targeted treatments

What is ATLL and who gets it?

Adult T-cell leukaemia/lymphoma (ATLL) is a rare type of non-Hodgkin lymphoma (NHL) that develops from a T lymphocyte (T cell). Our overview page explains what T-cell lymphoma is.

ATLL is associated with human T-lymphotropic virus type 1 (HTLV-1). Everyone who develops ATLL has been infected with HTLV-1. However, most people infected with HTLV-1 do not go on to develop lymphoma. ATLL develops in around 1 in 20 people with HTLV-1, usually 10–30 years after infection with HTLV-1.

HTLV-1 is rare in the UK. It is more common in other parts of the world like southern Japan, the Caribbean basin, Central and South America, parts of central Africa, Iran and Romania. The main way the virus is transmitted (spread from person-to-person) is thought to be through breast milk. HTLV-1 can also be transmitted through blood transfusions and sexual intercourse.

ATLL is slightly more common in men. It can affect adults of any age but is most common around the age of 55.

There are 4 different subtypes of ATLL that behave in different ways:

  • 2 aggressive (fast-growing) subtypes are lymphoma-type ATLL and acute ATLL
  • chronic (long-lasting) ATLL, which usually grows more slowly
  • smouldering ATLL, which the slowest-growing type.

Most people with ATLL have aggressive subtypes.

ATLL transforms (changes) into a faster-growing type in around 1 in 4 people with chronic or smouldering ATLL.

Back to top


As ATLL can behave in different ways, symptoms can vary.

Symptoms of chronic and smouldering ATLL

Chronic ATLL commonly causes:

  • skin rash
  • slightly enlarged lymph nodes (glands) and sometimes slight enlargement (swelling) of the liver and spleen (an organ of the immune system)
  • high numbers of lymphocytes (a type of white blood cell) in the blood.

Smouldering ATLL may cause no symptoms in some people. However, it is common to have a skin rash. Abnormal T cells might be seen in a routine blood test. The lungs might be also affected.  

Symptoms of acute and lymphoma-type ATLL

The 2 fast-growing types are distinguished by whether they mostly affect the blood or the lymph nodes:

  • The acute form is leukaemic, which means lots of abnormal T cells are found in the blood. Most people also have enlarged (swollen) lymph nodes.
  • The lymphoma form causes lots of enlarged lymph nodes, but does not affect the blood.

These types of ATLL can cause:

  • enlarged liver and spleen
  • hypercalcaemia (high levels of calcium in the blood), which can cause various symptoms like nausea, constipation, weakness, tiredness and confusion. It can cause heart and kidney problems, so needs to be treated quickly
  • skin rash; you might have widespread, itchy red patches; raised, solid areas of skin and swellings can also occur and might ulcerate (break down)
  • other systemic (whole body) symptoms like night sweats and fevers.

In the fast-growing types of ATLL, symptoms might come on very quickly.

ATLL can involve (be growing in) the bone marrow (the spongy tissue in the centre of bones where blood cells are made). Other organs might be affected and the lymphoma can sometimes be found in the central nervous system (brain and spinal cord).

Most people with the acute and lymphoma types of ATLL have advanced-stage (widespread) disease when they are diagnosed.

Back to top


T-cell lymphomas are rare, so it is difficult to determine which treatment gives the best outcome. You might be asked if you would like to take part in a clinical trial to help test new and current treatments.

ATLL can be difficult to treat and it is common for the lymphoma to relapse (come back) after treatment.

Treatment depends what type of ATLL you have and how it affects you.

Treatment of slow-growing ATLL

If you are well and you have smouldering ATLL or chronic ATLL that appears to be growing slowly, your doctor might suggest you have no treatment at first but are closely monitored instead. This is called active monitoring or ‘watch and wait’.

If ‘watch and wait’ is suggested for you, it means it is in your best interests to keep an eye on your lymphoma and to save active treatment for when it is needed. There is a lot of evidence that people do just as well in the long term on ‘watch and wait’ for slow-growing lymphoma as do people who are treated immediately.

Most people have antiviral treatments like zidovudine (Retrovir®) and alpha-interferon. These help to fight HTLV-1 and slow the growth of ATLL.

A newer, targeted drug might be available, usually through a clinical trial.

Treatment of fast-growing ATLL

People with fast-growing ATLL are usually treated with chemotherapy.

Some people with chronic ATLL have a faster-growing form and are also treated with chemotherapy.

The most common chemotherapy regimen (combination of drugs) used for ATLL is CHOP, which is made up of:

  • cyclophosphamide
  • doxorubicin (hydroxydaunorubicin
  • vincristine (Oncovin®)
  • prednisolone (a steroid).

Your doctor might suggest a more intensive chemotherapy regimen if you are well enough.

If your doctor thinks you are at high risk of your lymphoma affecting your central nervous system (CNS; brain and spinal cord), or relapsing (coming back) there, they can give you chemotherapy that crosses the blood-brain barrier (a barrier of cells and blood vessels that only lets certain substances reach the brain, protecting it from harmful chemicals and infections). This is called CNS prophylaxis. The drugs may be given intrathecally (by lumbar puncture into the fluid around the spinal cord).

Most people have antiviral treatments like zidovudine (Retrovir®) and alpha-interferon. A newer, targeted drug might be available, usually through a clinical trial.

Your medical team should monitor you closely as it is common for people with ATLL to develop infections. Contact your medical team immediately if you have any symptoms of infection, including but not limited to:

  • fever
  • shivering
  • chills and sweating
  • feeling generally unwell, confused or disoriented
  • earache, cough, sore throat or mouth
  • redness and swelling around skin sores, injuries to intravenous lines
  • diarrhoea
  • a burning or stinging sensation when passing urine
  • unusual vaginal discharge or itching
  • unusual stiffness of the neck and discomfort around bright lights.

You are also monitored by blood tests for hypercalcaemia so you can be treated quickly if it develops.

If you are well enough and your lymphoma has been reduced by chemotherapy, your doctor is likely to recommend you have more chemotherapy together with a stem cell transplant. If a suitable donor is available, this might be an allogeneic (donor) stem cell transplant. An allogeneic stem cell transplant is a very intensive form of treatment, but can sometimes lead to a long-term remission (no evidence of lymphoma).

Back to top

Relapsed or refractory ATLL

It is common for ATLL to relapse (come back) after being in remission. Relapse is most common in the first year after treatment has been completed. Sometimes, the lymphoma is refractory (doesn’t respond) to treatment. There are limited treatment options for people with aggressive ATLL who do not respond to chemotherapy or whose lymphoma relapses. Your doctor can discuss your options with you. Your doctor might consider:

Back to top

Research and targeted treatments

There are several newer,, targeted drugs that can be effective in treating ATLL, either on their own or together with chemotherapy. These are usually only available if you are taking part in a clinical trial because they are still being investigated. You can find out more about clinical trials and search for a trial that might be suitable for you at Lymphoma TrialsLink.

Drugs being tested in ATLL that have not yet been approved in the UK include:

  • antibodies like mogamulizumab. Mogamulizumab binds (attaches) to a protein called ‘CCR4’ on T cells. This can stimulate the immune system to kill the abnormal T cells.
  • cell signal blockers disrupt signals that keep cancer cells alive or allow them to grow. They act on different pathways in cells.
    • HDAC inhibitors like belinostat (Beleodaq®) or romidepsin (Istodax®), both of which are approved in the US for use in people with relapsed or refractory T-cell lymphoma
    • PI3-K inhibitors like duvelisib
    • PD1 or PD-L1 inhibitors like nivolumab and avelumab.
  • immunomodulatory drugs like lenalidomide (Revlimid®) and thalidomide. These affect the activity of the immune system in several different ways. They can help the immune system to attack the lymphoma cells and prevent the lymphoma from growing.
  • proteasome inhibitors, like bortezomib (Bortezomib Accord or Velcade®) and carfilozomib. These disrupt the balance of proteins in cells, causing them to die.

New drugs are being developed and tested all the time. This is not intended to be a comprehensive list of drugs in development.

Back to top


When your treatment is finished, you have regular follow-up appointments at the hospital. You are usually seen every 1–3 months at first. Your follow-up appointments become less frequent as time goes on if you remain in remission.  

You should contact your medical team or GP if you develop any symptoms of lymphoma or have other concerns between your appointments. Your specialist might bring your appointment forward if they think they need to see you sooner.

Back to top

Further reading

Related content

Lymphoma TrialsLink

Find out more about clinical trials and search for a trial that might be suitable for you.