Clinical Hematology

Leukemia is the result of the rapid buildup of abnormal white blood cells. It’s not known exactly what causes leukemia in children, although it is most likely related to changes in the genes within blood cells, possibly as the result of a viral infection or other factors. These changes are not usually inherited from parents; in other words, having one child with leukemia does not typically mean siblings or other family members are at risk.

The buildup of abnormal blood cells in childhood leukemia can impact the body in a lot of different ways. Too many abnormal white blood cells can crowd out normal, healthy red blood cells and platelets, which prevents the healthy cells from doing their jobs.

For example, red blood cells carry oxygen to all parts of the body. A lack of red blood cells is called anemia, which can make people very tired and can make the heart work too hard. Platelets help the blood clot, which stops bleeding. A low number of platelets usually means people bruise more easily and severely. The job of white blood cells is to fight infection by attacking infectious agents. The abnormal white blood cells of leukemia will sometimes attack healthy parts of the body.

symptoms may include:

• Bruising
• Bleeding
• Fatigue
• Fever
• Bone pain
• Infections

Symptoms like these do not always indicate leukemia. If they last a couple of weeks or more, however, a doctor can perform tests to determine the cause.

Every child is unique, so every case of childhood leukemia will have differences. By and large, though, nearly all cases of childhood leukemia are acute, meaning fast-growing (as opposed to chronic leukemias, which are slow-growing), and fall into one of two basic categories:

• Acute lymphoblastic leukemia (ALL): White blood cells go through several different phases as they mature. Acute lymphoblastic leukemia starts early in the white blood cell life cycle, when they are called lymphocytes. Cancerous lymphocytes are called lymphoblasts. About 75% of childhood leukemia patients have some form of ALL, which is most often treatable and curable, usually with well-established medicines such as chemotherapy. The overall survival rate for ALL is very good, approaching 90%, although it varies somewhat depending on the type of leukemia and the risk factors involved.
• Acute myeloid leukemia: Normally found in the bone marrow, healthy myeloid cells mature to become different types of white blood cells. In children with AML, cancerous myeloid cells, also called myeloblasts, reproduce too quickly and circulate in the blood. AML accounts for about 20% of all childhood leukemias. AML is also treated with chemotherapy, sometimes requiring a bone marrow transplant as well.
• Some children do get a type of leukemia called chronic myelogenous leukemia as well, but it’s very rare, accounting only for about 1% of cases. Acute leukemias are most common in children, whereas chronic leukemias are more common in adults.

Hodgkins lymphoma is a type of cancer that affects the lymphatic system, which is part of the body&;s germ-fighting immune system. In Hodgkin's lymphoma, white blood cells called lymphocytes grow out of control, causing swollen lymph nodes and growths throughout the body. Hodgkins lymphoma, which used to be called Hodgkins disease, is one of two general categories of lymphoma. The other is non-Hodgkin's lymphoma. Advances in diagnosis and treatment of Hodgkins lymphoma have helped give people with this disease the chance for a full recovery. The prognosis continues to improve for people with Hodgkins lymphoma.

Symptoms Signs and symptoms of Hodgkins lymphoma may include:

• Painless swelling of lymph nodes in your neck, armpits orgroin
• Persistent fatigue
• Fever
• Night sweats
• Losing weight without trying
• Severe itching
• Pain in your lymph nodes after drinking alcohol

When to see a doctor Make an appointment with your health care provider if you have any persistent signs or symptoms that worry you.

Lymphoma is a cancer of the lymphatic system. The lymphatic system is the body's disease-fighting network. It includes the lymph nodes, spleen, thymus gland and bone marrow. White blood cells within the lymphatic system called lymphocytes change and grow out of control. There are many types of lymphoma, but they are usually divided into two main categories: Hodgkin lymphoma (also called Hodgkin’s disease) and non-Hodgkin lymphoma (also known as non-Hodgkin’s lymphoma). Lymphoma types are based on how the cancer cells look under a microscope and how the disease progresses. Non-Hodgkin lymphoma most often occurs in adults, but some types can occur in children. It usually occurs in children over 3 years of age and most often occurs in boys.

The most common types of non-Hodgkin lymphoma that occur in children include the following:

• Lymphoblastic lymphoma
• Burkitt lymphoma
• Large cell lymphoma

These types of lymphoma grow quickly, and it’s important to find out which type a child has because the treatment for each type is different.

Symptoms depend on the area of the body where cancer is found and how fast the cancer grows. Symptoms may include:

• Painless swelling of the lymph nodes in the neck, underarm, stomach or groin
• Swelling of the head, neck, arms or upper body
• Trouble swallowing
• Shortness of breath or unable to lay down flat
• Persistent cough
• Swelling in the abdomen
• Night sweats
• Unexplained weight loss
• Fatigue
• Unexplained fever

Your child’s doctor will do a physical exam to check for swollen lymph nodes in the abdomen, neck or under the arm. The doctor will also order tests to diagnose non-Hodgkin lymphoma and to see how widespread the lymphoma is within the body if your child does have non-Hodgkin lymphoma. This process is called tumor staging. Your child may need the following tests:

• Blood tests
• Chest X-rays
• CT scan (or CAT scan)
• Ultrasound A PET scan
• MRI
• A lymph node biopsy
• A bone marrow aspirate and biopsy

Myelodysplastic syndromes are a group of disorders caused by blood cells that are poorly formed or dont work properly. Myelodysplastic syndromes result from something amiss in the spongy material inside your bones where blood cells are made (bone marrow).

Management of myelodysplastic syndromes is most often intended to slow the disease, ease symptoms and prevent complications. Common measures include blood transfusions and medications to boost blood cell production. In certain situations, a bone marrow transplant, also known as a stem cell transplant, may be recommended to replace your bone marrow with healthy bone marrow from a donor.

Symptoms

People with myelodysplastic syndromes might not experience signs and symptoms at first. In time, myelodysplastic syndromes might cause:

• Fatigue
• Shortness of breath
• Unusual paleness (pallor), which occurs due to a low red blood cell count (anemia)
• Easy or unusual bruising or bleeding, which occurs due to a low blood platelet count (thrombocytopenia)
• Pinpoint-sized red spots just beneath the skin that are caused by bleeding (petechiae)
• Frequent infections, which occur due to a low white blood cell count (leukopenia)

Diagnosis

A physical exam, medical history and tests might be used if your doctor suspects that you have a myelodysplastic syndrome. Tests might include:

• Blood tests.
• Removing bone marrow for testing.

When to see a doctor Make an appointment with your doctor if you have signs or symptoms that worry you.

Myeloproliferative neoplasm- Myeloproliferative neoplasms (MPNs) are rare, potentially life-threatening blood cancers that happen when your bone marrow makes too many blood cells. Blood cells include red blood cells, white blood cells and platelets. They’re made in the spongy tissue inside of your bones. With a myeloproliferative neoplasm, something goes wrong in the blood cell production process.

You likely won’t notice symptoms in the early stages. As your condition progresses, you may notice signs of an enlarged spleen (splenomegaly). Splenomegaly feels like fullness, pressure or discomfort below your ribs on your left side, where your spleen is located. While splenomegaly is a common symptom of most myeloproliferative neoplasms, it’s a less common symptom of essential thrombocytopenia.

Other symptoms depend on the specific myeloproliferative neoplasm. Chronic myelogenous leukemia and chronic neutrophilic leukemia Symptoms may include:

• Bone pain.
• Night sweats.
• Fever and fatigue.
• Bruising easily.
• Loss of appetite and weight loss. Essential thrombocythemia Symptoms may include:
  • Bruising easily.
  • Unexplained bruising or bleeding from your nose, mouth and gums.
  • Bleeding from your stomach or intestines.
  • Blood in your pee.

Symptoms may include:

• Headaches.
• Dizziness.
• Fatigue.
• Blurred or double vision.

Primary myelofibrosis You may experience symptoms of anemia (fatigue, weakness, shortness of breath). Other signs and symptoms may include:

• Pale skin.
• Night sweats.
• Fevers.
• Itchy skin.
• Abdominal fullness or filling up right away when you eat (early satiety).
• Weight loss.
• Bone pain.

• Complete blood count (CBC)
• Peripheral blood smear (PBS)
• Bone marrow biopsy
• Genetic testing