Learning about the different subtypes of chronic lymphocytic leukemia (CLL) and their varying outlooks and treatments is crucial when living with this condition. There are several kinds of CLL, a type of blood cancer that affects your lymphocytes (white blood cells). In CLL, the body makes too many abnormal lymphocytes that don’t work correctly to fight infections.

Doctors diagnose CLL based on which type of white blood cell is affected by abnormalities. They then group CLL into different categories based on how quickly the cancer cells grow.

Slow-Growing vs. Fast-Growing CLL

Your care team will use different laboratory tests to determine whether your leukemia is remaining stable or growing quickly. These tests look for specific proteins on the surface of your cells that affect how those cells grow.

Indolent CLL

Some people with CLL have leukemia cells that divide slowly. This is called indolent CLL. If you have this kind of leukemia, you may live with it for years without experiencing symptoms. Your body may have only slightly more lymphocytes than usual and slightly lower levels of other types of blood cells.

Because indolent CLL doesn’t often cause health problems right away, you may not need treatment for many months or years after being diagnosed. This type of leukemia management plan, called watchful waiting, involves getting regular blood tests and starting CLL treatment only when your condition gets worse.

Aggressive CLL

Your doctor may diagnose you with aggressive CLL if your leukemia cells grow rapidly. These cells can take over your immune system and start to crowd out your healthy red blood cells (cells that carry oxygen around your body) and platelets (small pieces of cells that help your blood form clots after an injury). This means that you’re more likely to have symptoms if you have aggressive CLL.

Symptoms may include frequent infections caused by a lack of functioning immune cells, or swollen lymph nodes, which lead to large lumps that can press against other organs and affect for example, your urinary habits or digestion. You may also have a swollen spleen, which can lead to pain, discomfort, or fullness on the upper left side of your abdomen.

Aggressive CLL usually needs to be treated right away. This strategy can help prevent additional health problems from developing. Your doctor will likely recommend starting chemotherapy or oral therapies soon after your diagnosis.

B-Cell CLL

As cited in Cancer.Net, most people with CLL — more than 19 out of 20 people — have B-cell CLL. This type of cancer affects B cells (B lymphocytes), cells that make antibodies (immune system proteins).

If you have this condition, your doctor will often simply refer to your disease as B-cell CLL. However, this type of cancer also has a few rare subtypes. Although B-cell CLL always develops from B cells, it can be caused by different genetic changes that may affect how these cells grow. Therefore, your doctor may let you know if you have a particular subtype caused by certain genetic mutations in your CLL cells. Not everyone has one of these subtypes, however.

Hairy Cell Leukemia

About 1 percent to 2 percent of adults with leukemia have hairy cell leukemia (HCL). Among members of MyLeukemiaTeam, 60 people say that they or a loved one has been diagnosed with this condition.

During HCL, gene changes within your B cells cause the cells to develop long, thin projections that make the cells look hairy.

HCL is usually indolent, which means it grows slowly. Your doctor may recommend a watchful waiting approach after you’re first diagnosed. Once symptoms begin, you will likely need to start chemotherapy or targeted therapy medications.

B-Cell Prolymphocytic Leukemia

Some doctors consider B-cell prolymphocytic leukemia (B-PLL) to be a subtype of CLL, affecting about 1 percent of people with B-cell leukemia. However, others classify it as a completely different type of leukemia. More than 50 people on MyLeukemiaTeam say they have B-PLL.

B-PLL doesn’t usually occur on its own — it often develops when slow-growing CLL turns into more aggressive, faster-growing cancer. Because B-PLL causes the same symptoms as CLL, it can be hard to diagnose.

B-PLL is rare and research on the condition is minimal. As such, doctors don’t always know exactly how to treat it. B-PLL is often treated with different combinations of chemotherapy and immunotherapy. Younger people with CLL may be able to try hematopoietic stem cell transplantation (a medical procedure that replaces damaged stem cells with healthy ones to promote cell growth). Doctors often recommend that people with B-PLL enroll in clinical trials. These are research studies that involve testing new treatments on people to find out if they are safe and effective.

T-Cell CLL

Some cases of CLL develop from T cells (T lymphocytes). These are immune cells that help the body kill germs and fight infected cells. T-cell CLL can also be divided into different subtypes.

T-Cell Prolymphocytic Leukemia

T-cell prolymphocytic leukemia (T-PLL) affects about 1 percent of those with CLL, making it the most common type of leukemia involving mature T cells for adults. More than 40 MyLeukemiaTeam members say they have T-PLL. All adults can develop the condition, but it’s most common in older men.

T-PLL is usually an aggressive type of cancer. Unlike some other types of CLL, it can lead to skin symptoms such as a rash or lesions (abnormal areas of skin). It’s treated with some of the same therapies recommended for B-cell CLL.

Large Granular Lymphocytic Leukemia

Large granular lymphocytic leukemia (LGL) is a rare type of cancer, making up about 2 percent to 5 percent of chronic lymphoproliferative disorders, per the journal Blood. Chronic lymphoproliferative disorders are conditions in which the body makes too many lymphocytes. T-cell LGL leukemia affects more than 80 members of MyLeukemiaTeam.

LGL leukemia can develop from T cells or natural killer cells. LGL leukemia may be either indolent or aggressive.

Nearly one-third of those with LGL leukemia have rheumatoid arthritis, in which the immune system attacks the joints, leading to joint pain or swelling.

Doctors typically recommend treating LGL leukemia with medications that change the way the immune system works, including methotrexate (Otrexup), cyclophosphamide (Cytoxan), and cyclosporine (Gengraf). Clinical trials also offer a way to try out new potential therapy options.

Adult T-Cell Leukemia/Lymphoma

In North America, adult T-cell leukemia/lymphoma (ATLL) makes up about 1 percent to 2 percent of cases of T-cell lymphoma, as cited in the Journal of Oncology Practice. Nearly 50 people on MyLeukemiaTeam have the condition.

There are four main subtypes of ATLL:

• Acute ATLL — An aggressive type of leukemia that leads to typical CLL symptoms and is also known as the most common ATLL subtype
• Lymphomatous ATLL — Grows aggressively and is similar to lymphoma, with cancer cells found in the lymph nodes
• Chronic ATLL — Often indolent and causes lymphoma symptoms as well as skin issues
• Smoldering ATLL — An indolent condition that usually only causes very mild skin or lung symptoms

ATLL often leads to a poor prognosis (outlook) but can be treated with chemotherapy.

Sézary Syndrome

Sézary syndrome is a leukemic type of cutaneous T-cell lymphoma (CTCL) — T-cell lymphoma that affects the skin. Cleveland Clinic reports that about 15 percent of CTCL cases are classified as Sézary syndrome. Fewer than 10 people on MyLeukemiaTeam say they have Sézary syndrome.

People with Sézary syndrome typically have skin issues such as redness, dryness, itchiness, and skin tumors. Some people may also experience symptoms like hair loss, nail changes, or swelling in the legs or arms. Although Sézary syndrome is technically a type of lymphoma, it causes high levels of cancer cells in the blood, making it similar to leukemia.

Sézary syndrome is an aggressive disease, meaning it spreads fast. In addition to typical leukemia treatment options, Sézary syndrome may be treated with therapies that target the skin, such as ultraviolet light treatments.

CLL and Lymphoma

CLL is also connected to some types of lymphoma. In fact, CLL is the same condition as small lymphocytic lymphoma (SLL). Both conditions are caused by cancerous lymphocytes. Your doctor may diagnose you with a type of CLL if the cancer cells live in the blood circulating around your body and bone marrow (the soft tissue found inside certain bones). You may get an SLL diagnosis if your cancer cells are mostly in your lymph nodes.

CLL or SLL may also turn into a different type of aggressive lymphoma. This condition, called Richter’s syndrome, is rare but may be treated with lymphoma therapies.

If you’re living with CLL, knowing the various subtypes is important for finding the best treatment and predicting the outcome. By identifying the specific type of CLL you have, doctors can customize a treatment plan to fit your needs and increase the likelihood of success.

Talk With Others Who Understand

MyLeukemiaTeam is the social network for people with leukemia and their loved ones. On MyLeukemiaTeam, more than 14,000 members come together to ask questions, give advice, and share their stories with others who understand life with leukemia.

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