Pediatric Hematology and Oncology

What Are Pediatric Hematological Diseases?

Pediatric hematology covers two main groups of diseases: benign (non-cancerous) and malignant (cancerous). Some of these diseases are:

• Iron deficiency anemia: It is the most common cause of anemia among children worldwide and in Türkiye. It is seen especially during periods of rapid growth, such as 0–24 months of age and adolescence.

• Thalassemia (Mediterranean anemia): In children, Mediterranean anemia is inherited genetically from the family through genes. It is more common in our country and the Mediterranean basin than in the rest of the world. In thalassemia, the body's ability to produce normal hemoglobin is genetically impaired, and defective hemoglobin is produced. Carriers lead normal lives but pass the genes on to future generations. Children with the disease known as thalassemia major depend on blood transfusions to live. The definitive treatment is bone marrow transplantation.

• Sickle cell anemia: It is one of the most common inherited diseases affecting red blood cells. Normally, red blood cells are round and flexible, so they can easily reach every part of the body and carry oxygen to the cells. In sickle cell anemia, however, red blood cells become crescent-shaped, stiff and inflexible. As a result, blood flow is blocked and tissues cannot receive enough oxygen. In addition, the misshapen red blood cells do not live as long as normal red blood cells, which can lead to severe anemia.

• Hemophilias: Hemophilias occur as a result of partial or severe deficiencies of the factors that enable blood to clot. In this disease, clinical symptoms vary depending on the level of the missing factor. Joint bleeding, abdominal bleeding and, in severe factor deficiencies, life-threatening bleeding including intracranial hemorrhage may occur.

• Aplastic anemia: It is a rare but serious blood disorder. It is known as the condition in which the bone marrow cannot produce sufficient red blood cells (erythrocytes), white blood cells (leukocytes) and platelets. Patients with aplastic anemia experience severe infections, anemia, bleeding and bruising.

• Von Willebrand disease (VWD): VWD is a common inherited disorder that prevents blood from clotting properly. Because the blood cannot clot, patients experience bleeding that is hard to stop and bruise easily. Women may have heavy menstrual bleeding. Some patients may also develop anemia due to prolonged bleeding.

• Acute Lymphoblastic Leukemia (ALL): It is a type of cancer caused by the uncontrolled and excessive proliferation of white blood cells produced in the bone marrow. Commonly known as blood cancer, this disease is one of the most common cancers of childhood. Acute Lymphoblastic Leukemia (ALL) is the most common type (85%), while Acute Myeloid Leukemia (AML) is less common. Treatment is chemotherapy. Stem cell transplantation is performed in high-risk patients and those who do not respond to treatment.

What Are the Symptoms of Pediatric Hematological Diseases?

The symptoms of pediatric hematological diseases vary depending on the affected cell.

Erythrocyte disorders: Anemia is a group of diseases characterized by insufficient oxygen delivery to the tissues due to a shortage of red blood cells or impaired red blood cell function.

• Iron deficiency anemia: It may present with weakness, fatigue, loss of appetite, pallor and pica, which is eating non-food substances such as soil, paper, ash, clay or ice.

• Thalassemia: In children, symptoms of Mediterranean anemia usually begin after the first 6 months of life. Loss of appetite, slowed development, rapid heartbeat, pale skin, jaundice, changes in the shape of the skull and facial bones, and shortness of breath may occur.

• Sickle cell anemia: Children usually begin to experience symptoms in the first year of life. The most common symptom of the disease is anemia. Due to anemia, the child may look pale and tired. Because crescent-shaped hemoglobin does not live as long as healthy hemoglobin, a substance called bilirubin is released each time it breaks down. When there is too much of this substance in the body, jaundice develops. Another possible symptom is pain. The cells can get stuck as they pass through the blood vessels. This blocks blood flow and causes pain. This pain caused by blockage usually occurs in the chest, arms and legs. In young children, it may appear as swelling in the fingers and toes.

Platelet and Clotting Factor Deficiencies:

• Immune thrombocytopenia (ITP): It usually appears suddenly after infections such as upper respiratory tract infections or diarrhea, with red spots all over the body that do not fade when pressed, as well as nosebleeds and gum bleeding.

• Von Willebrand disease: It should be considered in cases of bleeding that is hard to stop after minor surgical procedures, frequent nosebleeds, gum bleeding, abnormal bruising in various parts of the body, and heavy menstrual bleeding in adolescents.

Leukocyte (White Blood Cell) Disorders:

• Acute Lymphoblastic Leukemia: Symptoms of leukemia in children may include persistent fever, palpitations, weakness, fatigue, pallor, easy bruising, bleeding from the gums and nose, joint pain, weight loss and enlarged lymph nodes.

Diseases Affecting All Three: Red Blood Cells, White Blood Cells and Platelets:

• Aplastic anemia: It is a bone marrow failure condition in which the bone marrow cannot produce red blood cells, white blood cells and platelets. It may be congenital or acquired. It may present with weakness, fatigue, easy bruising, bleeding that is hard to stop, frequent infections and persistent fever.

If your child has one or more of these symptoms, it is recommended that they be examined by a Pediatric Hematology specialist. Your doctor will evaluate the symptoms and, with the help of diagnostic methods, diagnose your child's condition, if any.

How Are Pediatric Hematological Diseases Diagnosed?

There are many diagnostic methods used for pediatric hematological diseases. The pediatric hematology specialist plans the tests according to your child's medical history and examination. The most basic tests are the complete blood count and the peripheral blood smear. A complete blood count determines the status of red blood cells, white blood cells and platelets, and whether they are low or higher than normal. A peripheral smear is the process of spreading a drop of blood on a glass slide and examining the blood cells under a microscope. The most basic bleeding and clotting tests are aPTT, INR, PT and bleeding time; these are first-line tests that measure whether the clotting function is healthy. In diagnosing leukemia, lymphoma, aplastic anemia or bone marrow failure, a sample may additionally be taken from the bone marrow (aspiration) and a biopsy performed. The type of leukemia is determined with special tests called flow cytometry. By taking a sample of cerebrospinal fluid from the lower (lumbar) part of the spine, it is determined whether leukemic cells are present in the brain.

How Are Pediatric Hematological Diseases Treated?

The treatment of pediatric hematological diseases varies according to each disease and each child.

• Depending on the cause of anemia, iron or Vitamin B12 treatment may be needed, and in severe diseases such as thalassemia major, stem cell transplantation may be required.

• In diseases affecting white blood cells, such as leukemia and lymphoma, chemotherapy, blood product transfusions and stem cell transplantation may be required.

• Among bleeding and clotting disorders, hemophilias may require replacement of the missing factors to stop bleeding, while immune thrombocytopenia (ITP) may require IVIG and cortisone treatment.

Frequently Asked Questions About Pediatric Hematology

Which Diseases Does Pediatric Hematology Treat?

We have three types of cells produced in the bone marrow: red blood cells (erythrocytes), white blood cells (leukocytes) and platelets (thrombocytes). Pediatric hematology deals with diseases caused by a deficiency, dysfunction or uncontrolled overproduction of these cells.

Why Are Children Referred to Pediatric Hematology?

Your pediatrician may refer your child to a Pediatric Hematology specialist, usually in cases of treatment-resistant iron and vitamin B12 deficiencies, lymph node enlargement that does not respond to antibiotics, disorders of the bleeding and clotting system, or suspected leukemia or lymphoma.

How Is a Hematology Examination Performed?

As with any disease, a detailed medical history is taken. The family's and the patient's history are reviewed. A systemic examination is then performed. Based on the results, the Pediatric Hematology specialist plans the tests deemed appropriate.

Does Hematology Deal With Leukemia?

Yes, the hematology department deals with leukemia.

Why Is a Hematology Genetic Test Requested?

Genetic tests can be used to confirm the diagnosis of diseases and to shape the treatment method accordingly. Knowing the underlying genetics makes the child's treatment process more effective.

Which Tests Does Hematology Request?

These may include a complete blood count, clotting tests, bone marrow aspiration/biopsy, genetic and immunological tests, and imaging methods.

What Is Checked in a Hematology Test?

A complete blood count examines erythrocytes, hemoglobin, platelets, leukocytes and hematocrit; clotting tests examine PT, INR and aPTT. A bone marrow biopsy examines the structure and number of cells.

What Are the Symptoms of Leukemia in Children?

1. As a result of anemia caused by a shortage of red blood cells (erythrocytes):

   1. Pallor,

   2. Weakness, fatigue, exhaustion,

   3. Heart palpitations,

   4. Loss of appetite




2. Due to a shortage of white blood cells (leukocytes):

   1. Fever

   2. Infections

   3. Mouth sores




3. Due to a shortage of platelets (thrombocytes):

   1. Easy bruising (bruises below the knees are generally considered normal in children; what is meant here is bruising in unexpected areas),

   2. Gum bleeding,

   3. Nosebleeds (especially from both nostrils),

   4. Red spots on the skin that do not fade when pressed (petechiae, purpura),

   5. More rarely, internal bleeding (e.g. intracranial hemorrhage) may occur.

These symptoms may resemble those of other diseases, so it is recommended that you consult a specialist for the most accurate diagnosis.

How Is Leukemia Detected in Children?

Based on the symptoms listed above, the Pediatric Hematology specialist diagnoses leukemia using a complete blood count, peripheral smear, certain blood tests and samples taken from the bone marrow. Chemotherapy treatment is then started.