Acute Myeloid Leukemia (AML) - Specialists and Information

Most blood cells are produced in the bone marrow, a spongy tissue found inside the body’s large bones. 

Normally, the body produces only as many cells as it needs to replace. Blood cells develop from stem cells in the bone marrow. 

These divide and develop into myeloid and lymphoid cells. These precursor cells eventually differentiate into blood cells through various intermediate stages.

In AML, a precursor of the myeloid cell becomes abnormal, divides uncontrollably, and multiplies. The non-functional blood cells that result from this process are also called myeloid blasts.

The degeneration of the myeloid cell is caused by a genetic mutation in the bone marrow. 

There are various risk factors for this:

• Ionizing radiation
• Genetic disorders such as trisomy 21
• Increased exposure to chemical substances such as benzene
• Cytostatic drugs (substances that inhibit cell growth)

The symptoms of acute myeloid leukemia usually develop rapidly within a few weeks. The excessive production of immature myeloid blasts leads to a shortage of healthy blood cells. 

In addition, the leukemic cells also invade internal organs, causing various symptoms.

A shortage of red blood cells (erythrocytes) is medically referred to as anemia. 

Typical symptoms of this type of blood deficiency include:

• Paleness
• Fatigue and 
• exhaustion

A decrease in white blood cells (leukocytes), which are an important part of the immune system, leads to:

• Fever
• Increased susceptibility to infections of all kinds
• Platelets, which play a crucial role in blood clotting, are also lacking. 

This results in:

• Bruises
• Small pinpoint hemorrhages on the skin (petechiae)
• Frequent nosebleeds and 
• Prolonged bleeding times following minor injuries

If the spleen or liver is affected by immature blasts, they may swell. This is also referred to as (hepat)splenomegaly. 

Lymph nodes in the neck, groin, or armpits may also become swollen. The spread of leukemia cells to the bones can lead to bone pain.

In rare cases, leukemia also affects the spinal cord or the meninges. 

This can result in neurological symptoms such as:

• nerve paralysis
• Headaches, or 
• Vision problems 

The presence of blasts in the skin is also relatively rare and can lead to skin manifestations that are sometimes very noticeable. 

Some patients, however, show hardly any symptoms. As a result, doctors often diagnose leukemia in these cases by chance during a routine examination.

Hematomas are common in acute myeloid leukemia @ KMPZZZ /AdobeStock

In many cases, doctors discover leukemia more by chance. Patients usually present with nonspecific symptoms. 

Suspicion of acute myeloid leukemia is confirmed during a physical examination, particularly if the spleen, liver, or lymph nodes are enlarged. Blood tests usually reveal anemia with a deficiency of red blood cells.

White blood cells and platelets may also be deficient. 

In acute leukemia, the erythrocyte sedimentation rate (ESR) is significantly elevated. 

Under the microscope, the characteristic myeloid blasts can also be identified. Despite these fairly clear findings, a bone marrow examination is required to make an accurate diagnosis.

To do this, the doctor takes a bone marrow sample from the iliac crest under local anesthesia. 

Microscopic examination then reveals a large number of blasts and, at the same time, a reduction in normal cells. 

Imaging techniques (ultrasound, X-ray, computed tomography, and magnetic resonance imaging) reveal whether the immature precursor cells have invaded internal organs.

Involvement of the meninges and spinal cord can only be diagnosed through a cerebrospinal fluid (CSF) analysis.

Doctors use a needle to extract cells from the bone marrow for microscopic examination @ FrogMugiArt /AdobeStock

The treatment of choice for acute myeloid leukemia is intensive chemotherapy, which is administered in several phases: 

During the induction phase, patients receive high doses of chemotherapy drugs such as cytosine arabinoside. This is intended to reduce the number of abnormal cells. 

During the consolidation phase, doctors reduce the dose of the drugs. This second phase of chemotherapy lasts several months. 

In the subsequent maintenance therapy, patients must continue taking the chemotherapy drugs at a low dose for up to two years. 

In addition, an allogeneic stem cell transplant may be performed. In this procedure, the patient receives blood stem cells from a healthy donor. The stem cell transplant is performed as part of the consolidation phase in high-risk patients.

The prognosis for acute myeloid leukemia depends on various factors. 

The patient’s molecular profile is a key factor. 

These include:

• The patient’s age 
• Existing comorbidities 

These factors influence the likelihood of a relapse. The highest risk of relapse occurs within the first two to three years after the initial onset of leukemia. 

Therefore, regular follow-up visits are necessary even after successful treatment.

These include:

• A physical examination 
• Blood and bone marrow tests

Overall, the chances of a cure for AML have improved in recent decades. 

Since it is not possible to destroy the leukemic cells in all patients, the 5-year survival rate is only about 30 percent. 

This means that 30 percent of all patients with acute myeloid leukemia are still alive five years after diagnosis.