Leukaemia Classification - Common, Rare and More

Written by Hexahealth Care Team, last updated on 1 July 2023
     Leukaemia Classification - Common, Rare and More

A family member diagnosed with leukaemia? What exactly is it? How many types of leukaemia exist? How to treat it? Leukaemia is a complex and diverse form of cancer of the blood cells. Correct leukaemia classification is important to understand the condition better.

Understanding the classification of leukaemia is vital as it helps determine precise treatment approaches. With multiple types of leukaemia, tailored therapies can improve outcomes, guiding us towards effective management and potential cures. Read on to explore its types in detail!

What is Leukaemia?

Leukaemia is a complex and devastating blood cancer that originates in the bone marrow. It occurs when abnormal white blood cells multiply rapidly and uncontrollably, specifically the leukocytes responsible for defending the body against infections and diseases.

As these malignant cells multiply, they disrupt the production and function of normal blood cells, leading to various symptoms and complications. Leukaemia impairs the body's ability to fight infections, transport oxygen, and control bleeding.

Early detection and classification of leukaemia and accurate diagnosis are crucial for timely intervention and effective treatment strategies to improve patient outcomes and enhance their quality of life.

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Causes of Leukaemia

Leukaemia occurs with an abnormal mutation (changes) in the DNA of the new blood cells, and further multiplication of these mutated cells happens. It is vital to understand the causes of the disease to determine the correct leukaemia classification. It can be influenced by various risk factors contributing to this disease's development.

Meanwhile, the exact cause behind the mutation of the DNA is still under review. 

The bone marrow typically produces different types of blood cells, including red blood cells (RBCs), white blood cells (WBCs), and Platelets.

Risk Factors of Leukaemia

In addition to a family history of blood cancers, other risk factors can increase the chances of developing leukaemia. One should be aware of the classification of leukaemia and these risk factors to choose the best line of treatment.

  1. Smoking: Engaging in first or second-hand tobacco smoking is a well-known risk factor for leukaemia.

  2. Exposure to Certain Industrial Chemicals: Formaldehyde and benzene are common industrial chemicals that can elevate the risk of leukaemia when individuals are exposed to them for extended periods.

  3. History of Cancer Treatment: Those who have undergone radiation or chemotherapy for cancer have an increased risk of developing leukaemia. 

  4. Genetic Disorders: Certain genetic disorders, such as Down syndrome and Klinefelter syndrome, may be a risk factor for leukaemia.

  5. Other Forms of Blood Cancers: A previous history of blood cancer may increase your risk of developing leukaemia.

Note: It is crucial to understand that the existence of these risk factors does not ensure the development of leukaemia. However, these factors do impact the leukaemia classification to an extent.

It is recommended to speak with a healthcare practitioner who can provide individualised advice and direction if there are worries about the possibility of getting leukaemia.

Classification of Leukaemia

Understanding the classification of leukaemia is integral to deciding the best course of action. Leukaemia can be classified into two types based on how quickly it develops or worsens: acute and chronic. Below is a detailed look at both of them:

  1. Acute Leukaemia: This form is a rapidly progressing form of the disease and tends to show symptoms within a few weeks of leukaemia cell formation. It leads to the buildup of immature and non-functional blood cells in the bone marrow. Most commonly, it occurs in children.

  2. Chronic Leukaemia: This type progresses slowly and is relatively more common in adults than children. The symptoms may not show up for years. It causes the accumulation of relatively mature but still abnormal blood cells. However, the slower growth rate of chronic leukaemia can make it more challenging to treat effectively.

Each leukaemia classification has its characteristics and affects different age groups. Some varieties grow quickly and require immediate treatment, while others progress slowly, and treatment may take time to complete.

There are four main types of chronic and acute leukaemia classification include:

  1. Acute Lymphoblastic Leukaemia (ALL): ALL is commonly found in children and teenagers but may also occur in adults. It leads to the development of many lymphocytes.

    The disease progression rate is higher because it is acute but may be easier to treat than the chronic forms.

  2. Acute Myelogenous Leukaemia (AML): The type of cancer known as acute myeloid leukaemia is the most common type in adults. It develops when immature white blood cells, called myeloid blasts, grow uncontrollably.
    A quite aggressive form of cancer because of its faster progression, it requires urgent attention.

  3. Chronic Lymphocytic Leukaemia (CLL): CLL occurs when there is an outburst of development of white blood cells called lymphocytes. It mainly affects individuals between older adults and is rare in children.
    CLL generally grows gradually and may now show symptoms until it reaches later stages. Doctors usually monitor the disease and initiate treatment only if symptoms develop.

  4. Chronic myelogenous leukaemia (CML): CML is often caused by an abnormal number of unhealthy white blood cells.

    More common in middle-aged adults, it is rare in children. CML progresses slowly and has different phases.

Rare Types of Leukaemia

Leukaemia comes in distinctive forms, some less prevalent than others. The most crucial leukaemia classification for the rare types includes the following:

  1. Prolymphocytic Leukaemia (PLL): This type of cancer can develop when there is an out-of-control growth of white blood cells. Generally affects older adults, the symptoms of PLL may be similar to other types of leukaemia, such as flu-like symptoms, easy bruising, and unexplained weight loss.

  2. Large Granular Lymphocytic (LGL) Leukaemia: A chronic form of leukaemia in which the body produces abnormally large lymphocytes. When diagnosed with LGL leukaemia, patients usually experience flu-like symptoms, frequent infections, and unexplained weight loss.

  3. Hairy Cell Leukaemia (HCL): A rare type of chronic leukaemia that begins in the bone marrow. As the name suggests, the leukaemia cells, when seen through a microscope, appear as thin hair-like projections. It mainly affects adult men, with very few cases reported in young children.

  4. Myelodysplastic Syndromes (MDS): A category of disorders characterised by dysfunction in the bone marrow, which produces blood cells. This results in a deficiency of blood cells, including platelets, white blood cells, red blood cells, or occasionally all three.

  5. Myeloproliferative Neoplasms (MPNs): A group of blood disorders in which the bone marrow produces excessive specific blood cells - WBC, RBC, or platelets.
    There are six types of MPNs, each characterised by which specific blood cells are affected:

    1. Chronic Eosinophilic Leukaemia: In this type, there is an overproduction of eosinophils, which are a type of white blood cell that helps fight allergies.

    2. Chronic Myelogenous Leukaemia: Occurs when there are excess white blood cells in the bone marrow.

    3. Chronic Neutrophilic Leukaemia: There is an abnormal increase in neutrophils, which are white blood cells responsible for fighting infections.

    4. Essential Thrombocythemia: This condition results in a higher number of platelets formation.

    5. Polycythemia Vera: A higher production of red blood cells than normal causes this condition.

    A person's specific type of MPN determines the symptoms they experience, available treatment options, and overall prognosis.
  1. Adult T-cell Leukaemia/Lymphoma (ATLL): A rare form of leukaemia classification that affects a subset of white blood cells known as T-cells. The epidermis, lymph nodes, blood, and other body regions may contain it. There are four types of ATLL:

    1. Acute: This type develops rapidly and includes symptoms like fatigue, skin rash, and enlarged lymph nodes in the neck, underarms, or groyne.

    2. Lymphomatous: This type primarily affects the lymph nodes but can also cause high levels of white blood cells.

    3. Chronic: This type grows slowly and leads to increased lymphocytes in the blood, enlarged lymph nodes, skin rash, or fatigue.

    4. Smouldering: This type grows slowly and has mild symptoms, such as a few skin lesions.

      To diagnose ATLL, doctors may need to take a small tumour or abnormal skin tissue sample called a biopsy and examine the cells under a microscope.

Diagnosis and Treatment for Leukaemia

Leukaemia diagnosis and treatment require a thorough and multidisciplinary approach. Here are the aspects involved in the diagnosis of the disease based on the classification of leukaemia:

  1. Medical History and Physical Examination: The healthcare provider will gather information about symptoms and medical history and conduct a thorough physical examination.

  2. Blood Tests: Blood samples will be taken to analyse the complete blood count (CBC) and identify abnormal blood cells or other irregularities.

  3. Bone Marrow Aspiration and Biopsy: A small sample of bone marrow and a small piece of bone is obtained to examine the cells and determine the presence of leukaemia.

  4. Cytogenetic Analysis: Genetic testing is performed to identify specific chromosomal abnormalities associated with different types of leukaemia.

  5. Lumbar Puncture: In certain cases, a sample of cerebrospinal fluid is collected through a lumbar puncture to check for leukaemia cells in the central nervous system.

Once diagnosed, treatment strategies are tailored as per the individual's leukaemia classification, overall health, and other factors. Below are some of the most crucial treatment options:

  1. Chemotherapy: Anti-cancer drugs are administered orally, intravenously, or directly into the spinal fluid to kill leukaemia cells throughout the body.

  2. Radiation Therapy: High-energy X-rays or other forms of radiation are used to target and destroy leukaemia cells.

  3. Stem Cell Transplant: Healthy stem cells are introduced into the body to replace damaged or destroyed bone marrow cells after high-dose chemotherapy or radiation.

  4. Targeted Therapy: Drugs are used to specifically target certain molecules or genes that are involved in leukaemia cell growth.

  5. Immunotherapy: This treatment stimulates the immune system to recognise and attack leukaemia cells. 

  6. Clinical Trials: Participation in clinical trials provides access to innovative treatments tested for their effectiveness against leukaemia.

Risks and Complications of Untreated Leukaemia

Untreated leukaemia can lead to significant risks and complications, highlighting the importance of prompt diagnosis and treatment. Some of the potential consequences of untreated leukaemia include:

  1. Anaemia and Bleeding: The regular production of platelets and red blood cells is disrupted by leukaemia. Anaemia symptoms, including weakness, exhaustion, and shortness of breath, can result from untreated leukaemia. Additionally, a low platelet count can reduce the bleeding process.

  2. Organ Dysfunction: As leukaemia cells accumulate, they can infiltrate the liver, spleen, lymph nodes, and central nervous system. This infiltration can impair organ function, causing symptoms such as abdominal pain, enlargement of organs, neurological abnormalities, and breathing difficulties.

  3. Increased Infection Susceptibility: As leukaemia weakens the immune system, people are more susceptible to infections. Without proper care, the compromised immune system can lead to frequent and severe infections that can be fatal.

  4. Blood Clotting Abnormalities: Certain classifications of leukaemia can disrupt the body's natural clotting mechanisms, increasing the risk of abnormal blood clot formation. This can lead to deep vein thrombosis, pulmonary embolism, or other thrombotic events, which can be life-threatening. 

  5. Disease Progression: Without treatment, leukaemia is a progressive condition that can get worse over time. Leukaemia cells can invade different organs and tissues and proliferate abnormally, causing additional harm and complications.

When to See a Doctor?

For anyone who faces any abnormal symptoms, including the aforementioned or has concerns about their health, scheduling an appointment with a healthcare professional is recommended.

A doctor can evaluate your symptoms, perform necessary tests, and provide appropriate guidance or referrals if leukaemia or any other condition is suspected. They can also help you understand the leukaemia classification and choose the best course of action. 

Early detection and timely treatment can significantly improve outcomes for leukaemia and other types of cancer. While these symptoms can vary depending on the type of leukaemia, some common signs to watch out for include:

  1. Unexplained Fatigue or Weakness: Feeling excessively tired or weak, even with adequate rest, could be a symptom of leukaemia.

  2. Frequent Infections: Recurrent infections, such as frequent fevers, sore throat, or pneumonia, may indicate a weakened immune system, a sign of leukaemia.

  3. Bone or Joint Pain: Persistent bone or joint pain, often described as deep or aching, may occur in some cases of leukaemia.

  4. Unexplained Weight Loss: Significant and unexplained weight loss without any diet or physical activity changes could be a cause of concern.

  5. Excessive Sweating: Night sweats that are severe and recurrent, leading to soaking the bedclothes, can be a symptom of certain types of leukaemia.

  6. Easy Bruising or Bleeding: Unusual bruisings or bleeding, such as frequent nosebleeds, bleeding gums, or prolonged bleeding from cuts, may be indicative of a health condition.

  7. Enlarged Lymph Nodes or Swelling: Leukaemia can cause swelling or enlargement of lymph nodes, often in the neck, armpit, or groyne areas.


Understanding the classification of leukaemia is crucial in diagnosing, treating, and managing this complex group of blood cancers. Each type has unique characteristics, including the affected cells and progression patterns.

Awareness of leukaemia classification and types empowers patients and their families to participate in their treatment journey and make informed decisions actively. Turn to HexaHealth, where our seasoned experts can assist you in understanding the treatment and diagnosis of leukaemia in detail. Reach out to us and learn more today!

Suggested Reads

What is Leukaemia
Leukaemia Diagnosis
Acute Myeloid Leukaemia
Leukaemia vs Lymphoma

Frequently Asked Questions

What is the criteria for Leukaemia classification?

The criteria for leukaemia classification involve examining factors such as the specific cell type affected, the rate of cell growth, the presence of specific genetic abnormalities, and the maturity level of the affected cells.

These criteria help doctors classify leukaemia into different types, which guide treatment decisions.

What is leukaemia?

Leukaemia is a type of cancer that affects the bone marrow and blood. It occurs when there is an abnormal production of immature white blood cells, which leads to overcrowding of unhealthy cells and a deficiency of healthy blood cells.

What are the main types of leukaemia?

The main types of leukaemia based on the affected cell type and the speed of disease progression include acute lymphoblastic leukaemia (ALL), acute myeloid leukaemia (AML), chronic lymphocytic leukaemia (CLL), and chronic myeloid leukaemia (CML).

Can you explain acute lymphoblastic leukaemia (ALL) and its subtypes?

Acute lymphoblastic leukaemia (ALL) is a fast-growing cancer that primarily affects lymphoid cells, which are responsible for producing white blood cells.It is more common in children but can also occur in adults.

The subtypes of ALL include B-cell ALL and T-cell ALL, which refer to the specific type of lymphoid cell affected.

What is acute myeloid leukaemia (AML) and its subtypes?

AML is a fast-progressing cancer originating in myeloid cells, responsible for producing red blood cells, platelets, and certain white blood cells.

It affects both children and adults and is further classified into various subtypes based on the specific cell type affected and the genetic mutations present.

What are the different types of chronic lymphocytic leukaemia (CLL)?

Chronic lymphocytic leukaemia (CLL) is slow-growing cancer that affects mature lymphocytes, a type of white blood cell. CLL is more commonly seen in older adults and progresses slowly over time.

There are different types of CLL based on the specific characteristics of the cancer cells and the presence of certain genetic mutations.

Can you describe chronic myeloid leukaemia (CML) and its phases?

Chronic myeloid leukaemia (CML) is a slowly progressing cancer that begins in the myeloid cells, similar to AML. It is characterised by a specific genetic abnormality known as the Philadelphia chromosome. CML has three phases: chronic, accelerated, and blast crises. 

The chronic phase has fewer symptoms and progresses slowly, while the accelerated phase and blast crisis are more aggressive and associated with increased symptoms and complications.

Are there any other rare types of leukaemia?

Yes, there are rare types of leukaemia that are less commonly diagnosed. These include hairy cell leukaemia, adult T-cell leukaemia/lymphoma, large granular lymphocytic leukaemia, and rare subtypes of acute leukaemias.

How are the different types of leukaemia diagnosed?

Diagnosing leukaemia involves a combination of medical history evaluation, physical examination, blood tests, bone marrow aspiration and biopsy, and genetic testing.

These diagnostic tests help identify the specific type of leukaemia, determine the stage or progression of the disease, and guide treatment decisions.

What are the typical symptoms and signs associated with each type of leukaemia?

The symptoms and signs of leukaemia can vary depending on the type and stage of the disease. Common symptoms include:

  1. Fatigue

  2. Weakness

  3. Frequent infections

  4. Unexplained weight loss

  5. Swollen lymph nodes

  6. Easy bleeding or bruising

  7. Joint or bone pain

  8. Night sweats.

What are the common risk factors for developing leukaemia?

The exact causes of leukaemia are often unknown, but several recognised risk factors exist. Factors contributing to leukaemia risk include:

  1. Radiation exposure

  2. Specific chemotherapy or cancer treatments

  3. Genetic disorders (e.g., Down syndrome)

  4. Family history

  5. Chemical exposure (e.g., benzene)

  6. Weakened immunity.

How is the treatment approach different for different types of leukaemia?

Leukaemia treatment varies based on type, subtype, disease stage, patient health, and individual factors.

Treatment options may include chemotherapy, targeted therapy, immunotherapy, radiation, stem cell transplant, and sometimes watchful waiting or supportive care.

What are the treatment options for acute lymphoblastic leukaemia (ALL)?

Treatment options for acute lymphoblastic leukaemia (ALL) include chemotherapy, targeted therapy (such as monoclonal antibodies), radiation therapy, and stem cell transplantation.

The treatment approach depends on factors such as the age of the patient, a subtype of ALL, and the genetic characteristics of the leukaemia cells.

What are the treatment options for acute myeloid leukaemia (AML)?

Treatment options for acute myeloid leukaemia (AML) include chemotherapy, targeted therapy, radiation therapy, and stem cell transplantation.

The specific treatment regimen depends on factors such as the patient's age, overall health, genetic mutations in the leukaemia cells, and response to initial treatment.

What are the treatment options for chronic lymphocytic leukaemia (CLL)?

Chronic lymphocytic leukaemia (CLL) may not always require immediate treatment, especially in the early stages with no or minimal symptoms.

In cases where treatment is necessary, options include chemotherapy, targeted therapy, immunotherapy, and in some cases, stem cell transplantation. 

How is chronic myeloid leukaemia (CML) typically treated?

Chronic myeloid leukaemia (CML) is typically treated with a targeted therapy called tyrosine kinase inhibitors (TKIs). These medications, such as imatinib, dasatinib, and nilotinib, work by blocking the activity of the abnormal protein produced by the Philadelphia chromosome.

Are there any targeted therapies or immunotherapies available for leukaemia?

Targeted therapies and immunotherapies have transformed leukaemia treatment.

They specifically target cancer cells' molecular abnormalities to inhibit growth (tyrosine kinase inhibitors) and activate the immune system to attack leukaemia cells (monoclonal antibodies, CAR-T cell therapy).

What are the prognosis and survival rates for each type of leukaemia?

The survival rates for different types of leukaemia vary significantly.

  1. Chronic lymphocytic leukaemia (CLL) has a 5-year survival rate of 88%, indicating a relatively favourable prognosis.

  2. Acute lymphocytic leukaemia (ALL) has a 5-year survival rate of 71.3%, reflecting a reasonably good outcome.

  3. Chronic myeloid leukaemia (CML) has a 5-year survival rate of 70.6%, indicating a generally positive prognosis.

  4. Acute myeloid leukaemia (AML) has a 5-year survival rate of 31.7%, suggesting a more challenging prognosis compared to the other types.

Are there any new advancements in leukaemia treatment?

There have been notable advancements in leukaemia treatment in recent years. These include the development of targeted therapies, immunotherapies, and more personalised treatment approaches based on genetic profiling of leukaemia cells.

What is the role of bone marrow transplantation in leukaemia treatment?

Bone marrow transplantation (stem cell transplantation) is vital in leukaemia treatment, especially for high-risk or advanced cases.

Bone marrow transplantation replaces diseased marrow with healthy stem cells from a donor (allogeneic transplantation) or the patient's stored cells (autologous transplantation).

How can individuals support and manage their health while living with leukaemia?

Individuals with leukaemia should follow their treatment plan, take prescribed medications, and attend check-ups.

Maintain a healthy lifestyle with a balanced diet, exercise, rest, stress management, and avoid risks.

Seek emotional support, connect with advocacy groups, and build a strong support system for guidance and resources.


All the articles on HexaHealth are supported by verified medically-recognized sources such as; peer-reviewed academic research papers, research institutions, and medical journals. Our medical reviewers also check references of the articles to prioritize accuracy and relevance. Refer to our detailed editorial policy for more information.

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  6. Leukaemia | Cancer Research UK [Internet]. Cancerresearchuk.org. 2017.link
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Updated on : 1 July 2023


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HexaHealth Care Team

HexaHealth Care Team brings you medical content covering many important conditions, procedures falling under different medical specialities. The content published is thoroughly reviewed by our panel of qualified doctors for its accuracy and relevance.

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