Question

P.M., aged 4 years, has returned to the family physician because of a recurrent sore throat and cough. Her mother mentions unusual listnessness and anorexia. The physician notices several bruises on her legs and arms and one on her back. The physician orders blood tests and a course of antibacterial drugs. Test results indicate a hemoglobin level, thrombocytopenia, and a high lymphocyte count, with abnormally high numbers of blast cells. Following a bone marrow aspiration, a diagnosis of ALL is confirmed.

1. Describe the pathphysiology of ALL.

2. State the rationale for each of P.M.'s signs.

3. Explain the significance of blast cells in the peripheral blood.

4. Describe the effects of hypermetabolism in leukemia.

5. Explain how chemotherapy aggrevats the effectsof leukemia (refer to Chapter 20).

6. Describe the possible effects if leukemic cells infiltrate the brain.

7. Describe the pain associated with leukemia and the reason for it.

Answer 1

1] Acute lymphoblastic leukemia[ ALL ] , is a malignant disease of the bone marrow in which early lymphoid increase abnormally in number and begin to replace the normal hemopoitic cells of the marrow.As a result, the patients have too many immature white blood cells which outnumber the normal white blood cells .

The lymphoblasts replace the normal bone marrow elements, thus interfering drastically with the normal blood composition.

Without enough WBCs , the body has a hard time fighting diseases..

2] The child in our case study showed the typical symptoms of ALL :

Due to the abnormally low number of WBCs in her blood , her body was not able to figh common infections hence she had recurring fever, sore throat and cough.

The low haemoglobin count was responsible for her listlessness as the body cells did not get enough oxygen to produce energy by respiration.

The weigt loss or anorexia was caused due to lack of appetite induced by a feeling of fullness below the ribs, in the abdominal region.

Since, the platelet count also becomes very low in ALL patients, easy bleeding, dark red spots under the skin and frequent bruises wer observed in the patient.

3] Blast cells or myeloblasts, are the most immature cells of the bone marrow and are the precursor of all the mature cells in the blood. They mature before being released into the blood. If the peripheral blood sample shows the presence of more than 30% of nucleated blood cell , it can indicate to the condition of leukaemia. It means that the blast cell are released into the blood before they have matured ,thus disturbing the normal blood composition.

4] Hypermetabolism occurs when the body is in stress. It means that the body is not having a normal metabolic rate. For a patient suffering from leukaemia, the major fluid tissue i.e. the blood is affected. Blood is also the main means of transport in us. As a result transport of essential nutrients , oxygen ,CO2 etc are severely disrupted.

In the case of P.M. we saw that hypermetabolism resulted in extreme weight loss and lack of energy. In most cases of leukaemia the body will respond to hypermetabolism by loss of weight and lack of energy.

5] The chemotherapy drugs for treatment of leukaemia affect different people in different ways such as:

* Low levels of blood cells

* Increased risk of getting an infection

* Hair loss

* Mouth sores or ulcers

* Severe nausea and feeling sick and depressed

Since chemotherapy targets the fast dividing cell, it tends to affect the blood count by targetting the platelets as well as other blood cells.

6] When cancer cells move into the tissue fluid and target other organs, we call it metestasis . This means proliferation of the cancer cells to other parts of the body and it signals the last stages of cancer.

Cancerous WBCs can infiltrate the Central Nervous System[ CNS] at the diagnostic stage in about 30% of the children. To treat it , doctors aggressively use radiation therapy of the skull and chemotherapy. However, this is done at a high risk and at great cost because the side effects can be dangerous. They include brain tumors, developmental delay or even mental retardation.

7] Most cancers are painfull. Leukemia generally causes bone or joint pain because the bone marrow has become overcrowded with cancer cells. At times, the cancer cells might form a mass near the spinal cord's nerves or in the bone joints. The bone pains are generally in the long bones like in the thigh or arms. Many patients suffer from pain in the back and the chest. Again the reason is the build up and accumulation of masses of cancer cells , especially in the marrow, which destroys othe bone tissues and making the long bones and vertebrae more susceptible to fracture and collapse.