Hepatosplenic T-Cell Lymphoma

Hepatosplenic T-cell lymphoma (HSTCL) is a rare but aggressive form of non- Hodgkin’s lymphoma most common in adolescents and young adults. Only about 200 cases exist in medical literature.

Lymphoma is a group of cancers that develop in a category of white blood cells called lymphocytes. Based on how the cancer cells appear under a microscope, doctors split lymphomas into two main categories: Hodgkin’s and non-Hodgkin’s lymphoma.

Experts expect more than 80,000 people in the United States to receive a non- Hodgkin’s lymphoma diagnosis in 2022, compared with about 8,540 for Hodgkin’s lymphoma.

About 5% to 15% of non-Hodgkin’s lymphomas are peripheral T-cell lymphomas. This type of cancer tends to be aggressive and develops in white blood cells called T cells and natural killer cells.

Less than 5% of peripheral T-cell lymphomas are HSTCL.

What causes hepatosplenic T-cell lymphoma?

The development of lymphoma is still not well understood. Most people with HSTCL develop it with no known cause, but about 20% of the time, HSTCL develops in people with immunosuppression. It’s especially prevalent in people with:

  • autoimmune disorders
  • inflammatory bowel disease (IBD)
  • previous blood cancer
  • a solid organ transplant

Scientists have identified several gene mutations as risk factors for developing HSTCL.

About 63% of people with HSTCL have a genetic mutation called isochromosome 7q. About 50% of people have an extra copy of chromosome 8 (trisomy 8).

Who gets hepatosplenic T-cell lymphoma?

HSTCL is more common in adolescents and young adults. Half of people who receive a diagnosis of HSTCL are under the age of 34 years old, and most people are under the age of 40 years old.

According to a 2020 study, males seem to be about five times more likely than females to develop HSTCL.

For people with IBD, the risk seems to be highest in those taking long-term thiopurines either alone or with anti-tumor necrosis factor agents.

What are the symptoms of hepatosplenic T-cell lymphoma?

Initial symptoms of HSTCL tend to be vague and similar to other lymphomas, except for a lack of swollen lymph nodes. Symptoms may include:

  • general feeling of being unwell
  • fatigue
  • easy bruising or bleeding

People with HSTCL also tend to develop “B symptoms.” These include:

  • fever
  • drenching night sweats
  • unintentional loss of more than 10% of your body weight over 6 months

Abdominal pain due to spleen or liver enlargement is common. If the cancer is advanced, jaundice may occur.

How is hepatosplenic T-cell lymphoma diagnosed?

Diagnosing HSTCL can be challenging because its symptoms can mimic those of other cancers or infectious diseases.

The process of diagnosing HSTCL is similar to other types of non-Hodgkin’s lymphoma. Doctors or healthcare professionals usually perform a liver or bone marrow biopsy to make a diagnosis. They’ll analyze cells from the biopsy in a laboratory using specialized tests such as flow cytometry.

Imaging such as computed tomography (CT) scan or positron emission tomography/CT may be used to identify abnormalities in your liver and spleen.

What is the treatment for hepatosplenic T-cell lymphoma?

Due to the rarity of HSTCL, researchers have limited knowledge about how to best treat it. Most of what’s known has come from studies analyzing a small number of people treated at a single hospital, which makes it difficult to judge the effectiveness of various treatment options.

While there’s no standard treatment, in most studies, doctors treat people with HSTCL with chemotherapy and a bone marrow transplant if eligible.

Researchers have looked into various chemotherapy regimens with varying levels of effectiveness. At least two small studies have investigated the CHOP regimen, which consists of the drugs:

  • cyclophosphamide
  • doxorubicin (hydroxydaunorubicin)
  • vincristine (Oncovin)
  • prednisone

In one of these studies, 9 out of 21 people achieved complete remission, but half of the people lived less than 16 months. In the second study, only two out of six people treated with CHOP achieved remission. Remission only lasted an average of 8 months.

The role of bone marrow transplants in treatment remains under investigation. Some studies have found evidence that they may improve outcomes.

A doctor may consider two types of bone marrow transplant:

  • Autologous transplant: Medical staff take stem cells from your own bone marrow and return them after you receive large doses of chemotherapy.
  • Allogeneic transplant: You receive stem cells from a donor who’s a close genetic match. The donor is often a relative.

In a 2022 study, researchers presented a case of a young person with HSTCL who doctors cured with a combination of an autologous and allogeneic stem cell transplant.

What is the outlook for people with hepatosplenic T-cell lymphoma?

HSTCL tends to be aggressive, and the outlook for people with it tends to be poor. Estimates on the 5-year overall survival rate have been as low as 7%, with half of people living less than 10 months.

In a 2015 Dutch study, only 2 out of 12 people who receive a diagnosis of HSTCL lived for more than a year.

Despite the historically poor outlook for people with HSTCL, researchers are continuing to examine the best way to treat it. Due to the rarity of the disease, treatment protocols will likely continue to improve, and the survival rate will increase.

Many estimates of survival rates for HSTCL draw on research from decades ago. For example, in a 2021 study, researchers calculated the following overall survival rates:

But these estimates drew on data from a group of 123 people who received a diagnosis of HSTCL dating back to 1975.

Takeaway

HSTCL is a very rare type of non-Hodgkin’s lymphoma that tends to be aggressive, and the outlook for people with HSTCL is poor. It develops in a type of white blood cell called T cells in your liver and spleen.

Doctors are continuing to examine how to best treat HSTCL. Due to its rarity, the survival rate will likely continue to improve as researchers improve their understanding of the disease.

Talk with a doctor about whether you’re eligible for clinical trials that may give you access to state-of-the-art treatments. You can also find a list of current trials on the U.S. National Library of Medicine website.