Leukemia is a type of cancer that affects immune cells. Acute lymphocytic leukemia grows rapidly and requires immediate treatment, while chronic cases progress more slowly.

Leukemia causes immune cells in the bone marrow to become cancerous and spread to the bloodstream and organs.

Acute lymphocytic leukemia (ALL) is a form of leukemia that quickly worsens without treatment. It is more common in young children than adults. In contrast, chronic lymphocytic leukemia (CLL) grows slowly and typically only requires treatment after months or years.

Keep reading to learn more about the difference between ALL and CLL.

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ManyTrusted Source cases of CLL occur without symptoms in the early stages. A doctor may identify the condition while performing a blood test for another health issue.

ALL typically causes immediate symptoms that resembleTrusted Source the flu:

  • tiredness
  • lightheadedness and dizziness
  • pale skin
  • body aches
  • headaches
  • vomiting
  • loss of appetite

Both forms of leukemia can cause problems that relate to low blood cell counts, including anemia and leukopenia.

These issues can occur within days or weeks of ALL developing. However, they will not occur until the later stages in CLL. Symptoms could include:

  • pale skin
  • petechiae, which are flat, pinpoint spots under the skin that may appear red, purple, or brown depending on skin tone
  • recurring infections and infections that do not go away
  • easy bleeding and bruising, such as bleeding gums and severe nosebleeds
  • fevers and night sweats
  • spleen enlargement, causing feelings of fullness in the abdomen
  • liver enlargement
  • enlarged lymph nodes
  • bone or joint pain
  • weight loss

There are no scientific studies that report ALL becoming chronic.

CLL does not typically transform into acute leukemia, though there are reports of rare casesTrusted Source where this has happened. The condition is more likely to transform into Richter’s syndrome, a more aggressive form of lymphoma.

Genetic mutations that occur after birth, and are therefore nonhereditary, cause acute and chronic ALL and CLL. These mutations activate genes that increase cell growth and division while deactivating genes that slow cell growth and cause cell death.

Some types of genetic mutations in ALL and CLL are the same, while others may be more prevalent in one condition or the other.

According to a 2017 study, around 80% of people with CLL have at least one of four common chromosomal alterations or deletions. The American Cancer Society (ACS) notes that the most commonTrusted Source deletion involves part of chromosome 13.

Deletion can also affect chromosomes 11, 17, or an extra chromosome known as trisomy 12. CLL can also cause relate toTrusted Source other less common irregularities.

The ACS notes that translocationTrusted Source is the most common form of chromosomal change in ALL. This means that the DNA from one chromosome breaks away and attaches to another. The most common translocation in adult ALL relates to the Philadelphia ChromosomeTrusted Source, a break in DNA between chromosomes 9 and 22. Experts often refer to this as 9:22.

According to the ACS, CLL is the most commonTrusted Source type of leukemia in adults in the United States. Some risk factorsTrusted Source for ALL or CLL leukemia includeTrusted Source:

  • Age: Acute cases are more common than chronic cases in children, but people who are more than 50 years old are at the highest risk of both conditions.
  • Heritage: CLL is more common in Europe and North America than it is in Asia. Acute cases are more common in white people than African Americans.
  • Family history: A person with an identical twin who has ALL has an increased risk of developing the condition. Having a first-degree relative with CLL could double the risk of someone developing the condition.
  • Chemical exposure: CLL has links to long-term exposure to certain herbicides, chemotherapy drugs, and benzene.

Other risk factors for ALL include exposure to radiation and genetic syndromes, such as Down syndrome. Some viruses, such as the Epstein-Barr virus, can also cause the condition.

Doctors will performTrusted Source a thorough physical examination and take a full medical history to identify symptoms and risk factors for leukemia. They may also orderTrusted Source blood tests, such as a complete blood count with a blood smear.

People with ALL will have too many immature white blood cells, but chronic cases cause excess mature cells.

Taking bone marrow samples and biopsies are also important in diagnosing both conditions. Specialists will assess these samples for atypical structures or numbers of blood cells. They will also check for markers of leukemia to determine the type of leukemia and its progression.

Doctors will also use chromosome testing to check for mutations.

People with CLL may not require treatment. However, in these situations, doctors will closely monitorTrusted Source the condition’s progression and symptoms.

CLL and ALL have similar treatments, which includeTrusted Source:

  • chemotherapy
  • immunotherapy
  • targeted therapy
  • monoclonal antibodies
  • stem cell transplant

Although doctors treat both ALL and CLL with similar medications, the specific drugs they use and at which level of intensity will vary greatly.

There are no cures for either CLL or ALL. However, people with CLL typically have a positive outlookTrusted Source and can survive for years without treatment, according to the ACS. Most individuals will eventually require some treatment, which may occur in cycles.

Between 2014 and 2020, the 5-year relative survival rate for people with CLL was 88.5%Trusted Source.

Outlook among those with ALL will depend on various factors, including age, cancer progression, and health status. People, including children, typically respond well to treatment.

The 5-year survival rateTrusted Source for ALL is 90% for those under 15 years old and over 75% for those aged 15 to 19 years.

The National Cancer Institute estimates that people in general (undifferentiated by age) had a 72%Trusted Source 5-year survival rate between 2014 and 2020.

The ACSTrusted Source suggests that around 80% to 90% of adults with ALL will have complete remissions at some point during treatment. However, about half of these people will experience a recurrence, meaning the overall cure rate is in the range of 40%.

ALL and CLL are cancers that develop due to genetic mutations that are difficult to prevent. However, avoiding exposure to radiation, tobacco products, and benzene could help lower the risk.

For example, a 2021 study found that children with parents who smoked were more likely to develop ALL. Another studyTrusted Source from the same year found that most acute cases that develop in infants begin before birth.

A 2020 review indicates that most children who have a genetic mutation that increases the risk of leukemia do not develop the condition. This finding suggests a second mutation or certain environmental factors may be important in triggering leukemia.

Acute and chronic lymphocytic leukemia share similar causes, symptoms, and treatments. However, the progression and treatment requirements of these conditions and the outlooks of people who have them are different.

Acute cases develop rapidly and require immediate treatment, while chronic cases develop more slowly.