LEUKEMIA Flashcards
a malignant disease characterized by unregulated proliferation of one cell type.
LEUKEMIA
leukemia may involve any of the ____ or a ____ common to several cell lines
cell lines; stem cell
leukemias 2 major groups
chronic and acute leukemia
the onset is insidious, the disease is usually less aggressive, and the cells involved are usually more mature cells
chronic leukemia
the onset is usually rapid, the disease is very aggressive, and the cells involved are usually poorly differentiated with many blasts.
acute leukemia
Both acute and chronic leukemias are further classified according to the prominent cell line involved in the expansion:
If the prominent cell line is of the myeloid series it is a myelocytic leukemia (sometimes also called granulocytic)
If the prominent cell line is of the lymphoid series it is a lymphocytic leukemia
four basic types of leukemia
Acute myelocytic leukemia
Acute lymphocytic leukemia
Chronic myelocytic leukemia
Chronic lymphocytic leukemia
type of leukemia that includes myeloblastic, promyelocytic, monocytic, myelomonocytic, erythrocytic, and megakaryocytic
Acute myelocytic leukemia (AML)
type of leukemia that includes T cell, B cell, and Null cell
Acute lymphocytic leukemia (ALL)
type of leukemia that includes myelocytic and myelomonocytic)
Chronic myelocytic leukemia (CML)
a type of leukemia that includes plasmocytic {multiple myeloma}, Hairy cell, prolymphocytic, large granular cell lymphocytic, Sezary’s syndrome, and circulating lymphoma
Chronic lymphocytic leukemia (CLL)
predisposing factors of leukemia (etiology)
host factors
environmental factors
Some individuals have an _____ to develop leukemia
inherited increased predisposition
There is an increased incidence in those with an ______ or ________ of chromosomes (such as _____).
inherited tendency for chromosome fragility or abnormality ; those with increased numbers ; Down’s syndrome
Many of these diseases are characterized by _______.
chromosomal translocations
There is an increased incidence in those with ________.
hereditary immunodeficiencies
There is an increased incidence in those with chronic marrow dysfunction such as those with…
myeloproliferative diseases, myelodysplastic syndromes, aplastic anemia, or paroxsymal nocturnal hemoglobinuria.
Environmental factors
Exposure to ionizing radiation
Exposure to mutagenic chemicals and drugs
Viral infections
incidence of leukemia
Acute leukemias can occur in all age groups
Chronic leukemias are usually a disease of adults
ALL is more common in _____
children
AML is more common in _____
adults
CLL is extremely rare in ____ and unusual before the age of ___
children ; 40
CML has a peak age of ____
30-50
acute leukemias on the ff.
Age
Clinical onset
Course (untreated)
Leukemic cells
Anemia
Thrombocytopenia
WBC count
Lymphadenopathy
Splenomegaly
Age = all ages
Clinical onset = sudden
Course (untreated) = 6 mos. or less
Leukemic cells = immature >30% blasts
Anemia = prominent
Thrombocytopenia = prominent
WBC count = varibale
Lymphadenopathy = mild
Splenomegaly = mild
chronic leukemias on the ff.
Age
Clinical onset
Course (untreated)
Leukemic cells
Anemia
Thrombocytopenia
WBC count
Lymphadenopathy
Splenomegaly
Age = usually adults
Clinical onset = insidious
Course (untreated) = 2-6 years
Leukemic cells = more mature cells
Anemia = mild
Thrombocytopenia = mild
WBC count = increased
Lymphadenopathy = present;often prominent
Splenomegaly = present;often prominent
acute leukemia is a result of malignant transformation of a stem cell leading to _____
unregulated proliferation
acute leukemia is also a result of Arrest in maturation at the ______
primitive blast stage (Remember that a blast is the most immature cell that can be recognized as committed to a particular cell line)
clinical feature: Leukemic proliferation, accumulation, and invasion of normal tissues, including the ____________ cause lesions ranging from rashes to tumors.
liver, spleen, lymph nodes, central nervous system, and skin.
clinical feature: A humoral mediator from the leukemic cells may inhibit _______
proliferation of normal cells.
clinical feature: Failure of the bone marrow and normal hematopoiesis may result in ______
pancytopenia with death from hemorrhaging and infections.
lab diagnosis is based first on,
Finding a significant increase in the number of immature cells in the bone marrow including blasts, promyelocytes, promonocytes (>30% blasts is diagnostic)
lab diagnosis is based secondly on,
Identification of the cell lineage of the leukemic cells
peripheral blood
Anemia (normochromic, normocytic)
Decreased platlets
Variable WBC count
The degree of peripheral blood involvement determines classification
leukemic
subleukemic
aleukemic
increased WBCs due to blasts
leukemic
blasts without increased WBCs
subleukemic
decreased WBCs with no blasts
aleukemic
Classification of the immature cells involved may be done by
Morphology
Immunologic markers (immunophenotyping)
an experienced morphologist can look at the size of the blast, the amount of cytoplasm, the nuclear chromatin pattern, the presence of nucleoli and the presence of auer rods (are a pink staining, splinter shaped inclusion due to a rod shaped alignment of primary granules found only in myeloproliferative processes) to identify the blast type
Morphology
the myeloblast is a large blast with a moderate amount of cytoplasm, fine lacey chromatin, and prominent nucleoli. 10-40% of myeloblasts contain auer rods.
AML
in contrast to the myeloblast, the lymphoblast is a small blast with scant cytoplasm, dense chromatin, indistinct nucleoli, and no auer rods
ALL
help to classify the lineage of a leukemic cell (myeloid versus lymphoid)
Cytochemistry
found in the primary granules of granulocytic cells starting at the late blast stage. Monocytes may be weakly positive.
Myeloperoxidase
stains phospholipids, neutral fats and sterols found in primary and secondary granules of granulocytic cells and to a lesser extent in monocytic lysosomes. Rare positives occur in lymphoid cells
Sudan Black
used to identify monocytic cells which are diffusely positive. T lymphocytes may have focal staining
Nonspecific esterase
May be found in myeloblasts and lymphoblasts. T lymphocytes have a high level of ____ and this can be used to help make a diagnosis of acute T-lymphocytic leukemia.
acid phosphatase
located in the secondary granules of segmented neutrophils, bands and metamyelocytes.
Leukocyte alkaline phosphatase
Leukocyte alkaline phosphatase score
The LAP score is determined by counting 100 mature neutrophils and bands. Each cell is graded from 0 to 5. The total LAP score is calculated by adding up the scores for each cell.