Leukemia

1. Running head: ACUTE LYMPHOCYTIC LEUKEMIA IN CHILDREN 1
Acute Lymphocytic Leukemia in Children
Student’s Name
Institution

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Acute Lymphocytic Leukemia in Children
Acute lymphocytic leukemia (ALL) is a cancer that attacks the lymphocytes in the bone
marrow. After the invasion of the blood, the leukemia cells spread very fast to other body parts
such as lymph nodes, spleen, testicles and CNS. If not treated in time, ALL may become fatal
within a short period. Early blood-forming cells in the bone marrow can easily change to
leukemia cells. After their formation, the leukemia cells do not mature normally. They multiply
very fast, survive and grow in the bone marrow (Fiegl, 2016). Eventually, they leak into the
bloodstream and spread to other parts of the body where they interfere with the normal
functioning of the cells.
Epidemiology and incidences
Acute lymphocyte leukemia is a rare disease that contributes to about 1.3% of cancer cases in the
US. Although the overall leukemia cases have been stable since 1975, its rate has been
insignificantly increasing over the last two decades by 2.2% and 0.6% respectively. According to
the US and international statistics, the number of new cases per 100,000 patients was 1.7%.
Similar cases have been reported in other developed countries such as Germany (5.2%) and UK
(1%). It means that acute ALL accounts for about 35,000 new cancer cases annually. Moreover,
this disease was responsible for about 12,000 deaths in the US. The average 5-year survival rate
for ALL is estimated at 67.5%. Acute lymphocyte leukemia is strongly related to age with its
peak in childhood with an average age of 14 years. However, it is independent on gender but
varies with ethnicity. For example, Hispanics have the highest chances of diagnosis while the
trend is lowest among the Whites.

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Physiology and Pathophysiology
The lymphoid cells undergo different clonal rearrangements of their T-cell receptor genes. Upon
a successful completion of their genetic changes, these cells are undergo a controlled
proliferation process resulting into the production of normal B and T cells. These changes in
genes of lymphoid cells through somatic alteration may lead to unregulated proliferation and
clonal expansions. Then, the leukemic cells discharge penetrates the bone marrow and other
body parts, thus interfering with their normal functions resulting into the acute lymphatic
leukemia (Fiegl, 2016). These leukemic discharge signify a clonal spread of a cell. Such a trend
has been validated by cytogenetics, glucose-6-phosphate dehydrogenase characterization and a
thorough study of antigen-receptor gene rearrangements as well as X-linked constraint fragment-
length polymorphism.
These leukaemic cells copy many features of the normal lymphoid progenitor. Its genetic
defects include microscopic chromosomal rearrangements. Besides, translocations in
chromosomes are detectable in over 75% of leukemic cases. Moreover, genetic abnormalities
found in this disease are categorized according to functionality of oncogenic mutation. An
example of such a mutation is the activation of the ABL protein kinase through the
reorganization of BCR genes. This leads to a proliferative advantage. Profiling of these genes has
revealed a new Ph-like leukemia which is common among children. Patients with this type of
leukemia can be subdivided into ABL-class fusions, erythropoietin-receptor, cytokine receptor-
like factor 2 rearrangements, JAK-STAT activating mutations, unpopular kinase mutation and
RAS-pathway mutations.

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The regular occurrences of kinase-activating mutations found in Ph-like leukemia have
resulted into many groups to test the inclusion of a tyrosine kinase inhibitor and have revealed an
improvement in treatment results. Other gene disorganization may lead to gain or loss of
functional mutations involving transcription factors that play haematopoietic development. Other
mechanisms involving the formation of acute lymphocytic leukemia includes inactivation of
genes that suppress tumors and deleting gene rearrangements.
Clinical manifestations and assessments
ALL patients manifest symptoms related to direct infiltration of leukemic cells into the bone
marrow or other symptoms related to reduced production of elements of bone marrow. The most
common symptom is fever with no evidence of infection. Nonetheless, presence of fever among
these patients should follow with an examination of presence of infections followed by thorough
treatment, otherwise can be fatal. The most common causes of fatalities among ALL patients are
infections. Besides, patients often have reduced neutrophil counts despite the levels of their total
white blood cell counts. Consequently, such patients are at high risks of infections, which are
inversely proportional to their absolute neutrophil counts. Infections are common among patients
with less than 500/µL absolute neutrophil count, but their severity occurs when it decreases to
100/µL.
Other common symptoms include dizziness, fatigue and dyspnea. Some patients may
show signs of bleeding because of thrombocytopenia resulting from replacement of marrow.
Besides, about 10% of ALL patients show signs of disseminated intravascular coagulation during
the time of diagnosis. Such patients may demonstrate some thrombotic or hemorrhagic
complications. Others show physical lymphadenopathy, shortness of breath especially among
those with T-cell leukemia. Large amounts of leukemia cells that infiltrate marrow frequently are

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associated with severe bone pains which are atypically distributed (Abdul, 2013). Between 10-
20% of leukemia patients may show left upper quadrant fullness and early safety because of
splenomegaly.
Additionally, some patients may manifest symptoms of leukocytosis due to the presence
of huge number of lymphoblast in the peripheral circulation especially among patients with large
amounts of white blood cells counts.
Diagnostic testing
Procedures and tests applied in diagnosing acute lymphocytic leukemia include blood tests, bone
marrow tests, imaging tests and spinal fluid tests.
Blood tests: Such tests may show high levels of white blood cells, insufficient red blood cells and
platelets. A blood sample may also reveal the presence of blast cells which are common in the
bone marrow.
Bone marrow tests: During this test, a needle is used for removing a sample of bone marrow
from the hipbone. This sample is then tested in the lab for the presence of leukemia cells.
Doctors will then categorize the blood cells into specific groups according to their sizes and
shapes among other features. They also look for alterations in cancer cells and conclude whether
the leukemia cells originated from B or T lymphocytes. Such information help the doctor to
create a treatment plan.
Imaging tests: These tests involve the use of a computerized tomography scan, ultrasound or X-
ray that help in determining the extent of spread of cancer to the brain, spinal cord and other
body organs.

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Spinal fluid tests: This test involves collecting samples of spinal fluid. Then the doctor tests the
samples to verify the extent to which cancer cells have spread to the spinal fluid.
Clinical management and the effects on pathophysiology
Induction therapy. This phase involves killing most of the leukemia cells in the bone marrow and
blood and normalize the production of blood cells.
Consolidation therapy. This treatment phase aims at destroying remains of leukemia cells in the
body and other organs such as spinal cord and brain.
Maintenance therapy. This phase aims at preventing the regrowth of leukemia cells. At this
stage, lower doses are administered over a long period of time.
Preventive treatment to the spinal cord. At this phase, people diagnosed with ALL receives extra
treatments aimed at killing leukemia cells hidden in the central nervous system. Here,
chemotherapy drugs are directly administered into the fluid covering spinal cord.

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References
Abdul, G. (2013). Acute Leukemia Clinical Presentation. Leukemia. Doi: 10.5772/53531
Fiegl, M. (2016). Epidemiology, pathogenesis, and etiology of acute leukemia. Handbook of
Acute Leukemia, 3-13. Doi: 10.1007/978-3-319-26772-2_2.