Pediatric hematology and oncology

Question 1

What hemoglobin chains make up fetal hemoglobin (HbF), and adult hemoglobin (HbA and HbA2)?

Answer 1

HbF: Alfa- and gamma chains.
HbA: Alfa- and beta chains.
HbA2: Alfa- and delta chains.

Question 2

By what age is fetal hemoglobin replaced by adult hemoglobin?

Answer 2

Around 6 months of age.

Question 3

What are examples of causes of aplastic anemia in children?

Answer 3

Hereditary conditions: Diamond-Blackfan-anemia (isolated anemia). Fanconi’s anemia (pancytopenia).
Acquired conditions: Transient erythroblastopenia of childhood (TEC), infections, drugs, etc.

Question 4

What are examples of causes of hemolytic anemia in children?

Answer 4

Cell membrane disorders, such as hereditary spherocytosis.
Enzyme disorders, such as glucose-6-P dehydrogenase deficiency.
Hemoglobinopathies, such as thalassemias and sickle cell disease.

Question 5

What are examples of bleeding disorders in children?

Answer 5

Hemophilia A and B. Bleeding into joints and soft tissues. Caused by deficiency in factor VIII or IX.
vonWillebrand disease. Mucocutaneous bleeding, bruises, bleeding postoperatively.
Vitamin K deficiency.

Question 6

What are main causes of petechia in children?

Answer 6

Non-thrombocytopenic: Henoch-Schoenlein, sepsis, trauma.

Thrombocytopenia: ITP, DIC, leukemia.

Question 7

What is the role of chemotherapy in treatment of pediatric cancer?

Answer 7

Chemotherapy is crucial (and more effective than in adults).

Question 8

What are possible (late) side effects of chemotherapy?

Answer 8

Late effects:
Encephalopathy due to irradiation
Cardio-, oto-, nephrotoxic side effects of chemotherapy
Infertility
Endocrine disorders (hypopituarism, hypothyreoidism, precocious/delayed puberty, impaired growth)
Secondary malignancies

Question 9

What is the most common type of cancer in children? Are different malignancies most common in different age groups?

Answer 9

Acute lymphoblastic leukemia (ALL).

Yes, under the age of one year neuroblastomas are the most common form of malignancy.
Between the ages of 1 and 15 years acute leukemia is the most common.
From 15 years until 19 years of age lymphomas are the most common.

Question 10

What are warning signs of pediatric cancer?

Answer 10

Lasting reduced general condition
Enlarged lymphal nodes
Tumors
Anemia, bleedings, infections
Hepato-/splenomegaly
Bone or joint pain
Precocious puberty
Exophtalmus
Headache and nausea

Question 11

What can be acute complication of acute leukemia?

Answer 11

Hyperleukocytosis / Hyperleukocytosis / leukostasis. (White cell plugs seen in the microvasculature.)
Tumor lysis syndrome (causing hyperkalemia, -phosphatemia, and -uricemia.)

Question 12

What is the most common type of brain tumors in children?

Answer 12

Astrocytoma. (Second-most common medulloblastoma.)

Question 13

What tissue is the origin of neuroblastomas?

Answer 13

Adrenal medulla and sympathetic nervous system. (Derived from neural crest tissue.)

Question 14

What are common sites of metastasis from neuroblastomas?

Answer 14

Bone and bone marrow.

Question 15

What are molecular differences between adult and pediatric cancer?

Answer 15

Pediatric cancers have fewer mutations than adults cancer types (thus fewer targets for targeted therapy). available