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intro to leukemias
|a group of diseases in which the common abnormal characteristic is a malignant unregulated duplication (replication) of the formed elements (RBCs, WBCs, and/or platelets) from the bone marrow (hematopoietic system).
|What causes leukemia
|unknown but Most malignancies of the bone marrow are acquired generic, diseases meaning that most patients are not born with the illness but acquire it sometime later. Most leukemias are not localized, but rather are systemic.
|Are leukemias localized
|No they are systemic
|where do leukemias arise
|What are the two broad classifications of leukemia
|Acute and chromic leukemias
|What are some characteristics of acute leukemia
|abrupt onset, derived from immature cell forms (including blasts), poor prognosis, occurs in children/adults
|What are some characteristics of chronic leukemia
|slow onset, derived from mature cells (few blasts seen), better prognosis, occurs usually in adults
|Beyond acute/chronic leukemias how can they be further classified? briefly explain each and who can determine these classifications?
|lymphoid type of leukemia 2. myeloid type of leukemia Whether a leukemia is designated as “lymphoid” or “myeloid” is based on the types of blasts identified as being present. A pathologist makes this determination—not the technicians.
|5. What is the usual progression of malignant cells in the course of leukemia?
|• leukemic cells usually replace normal bone marrow cells and eventually will interfere with normal bone marrow function • leukemic cells may invade other organs • leukemia can/will eventually causes death, if not treated
|6. What does ALL stand for?
|Acute Lymphoblastic Leukemia
|7. Which cell type proliferates in ALL?
|Two major types of ALL have been recognized by the WHO: precursor B cell and precursor T cell.
|Lymphoblast vary in size but what is the most common size seen?
|The most common type seen is the small lymphoblast. It is 1-2.5 times the size of a normal lymphocyte.
|8. What age group of individuals is characteristically affected by ALL?
|ALL is primarily a disease of childhood: most cases occur between the ages of 2 and 10 years, ALL is rare in adults, but a peak incidence of ALL can occur around the age of 40.
|9. What is the general prognosis for ALL?
|ALL was considered a fatal disease before 1970, but today, ALL has a 90% complete remission rate and a 60% cure rate.
|what is the prognosis for ALL dependent on?
|The prognosis for ALL is dependent on age at the time of diagnosis (children do better than infants or teens)and also the immunophenotype
|what does lymphoblast "load" mean
|(meaning # of lymphoblasts seen upon diagnosis)
|what does immunophenotype mean
|either B cell and/or T cell presence
|10. What does AML stand for?
|Acute Myelogenous Leukemia
|11. What other “names” are given to AML?
|Acute Granulocytic Leukemia (AGL) and/ or Acute Nonlymphocytic Leukemia (ANLL)
|12. What age group is usually affected by AML?
|AML/AGL/ANLL is the most common family of leukemia in children younger than 1 year of age. It is rare in older children and adolescents, but a second incidence peak occurs at age 40 years
|13. Two organizations classify the acute anemias. Name them.
|World Health Organization (WHO) French-American-British (FAB)
|14. What four WHO classification schemes exist for AML? List them.
|AML with recurrent cytologic abnormalities AML with multilineage dysplasia AML and myelodysplasia as a result of therapy AML, not otherwise classified
|what does undifferentiated/nondifferentiated mean and what is the typical prognosis
|cells that cannot be correctly identified because they are so bizarre looking. Because theses cells a lot of times cannot be correctly identified, undifferentiated leukemias have a very poor prognosis.
|what does differentiated mean and what is the typical prognosis
|cells that can be correctly identified. Differentiated leukemias have a better prognosis than undifferentiated leukemias because the cells that make up a differentiated leukemia are identifiable, and therefore (possibly) treatable.
|16. What is meant by “hybrid” leukemias?
|A type of leukemia in which the blasts seen possess both myeloid and lymphoid characteristics.
|17. Define bilineal leukemias.
|A type of leukemia in which a MIXED population of cells expressing both lymphoid and myeloid characteristics is seen.
|18. Define biphenotypic cells.
|Individual leukemic cells that show both lymphoid and myeloid features.
|19. If a bilineal leukemia is showing a “synchronous” blood picture, what does it mean?
|A type of leukemia in which a MIXED population of cells expressing both lymphoid and myeloid characteristics is presenting at the same time.
|20. If a bilineal leukemia is showing a “metachronous” blood picture, what does it mean?
|A type of leukemic condition in which one leukemia type is followed by a relapse with a different type of leukemia, and a MIXED population of cells expressing both lymphoid and myeloid characteristics is seen with these leukemias.
|21. What is the most common type of leukemia seen today, and what age group is typically affected?
|CLL is the MOST COMMON type of leukemia seen today. This disease has such a slow, insidious onset, that a lot of times, it is discovered accidently when performing a CBC.
|Who is affected by CLL
|It affects twice as many males as females and the median age is at time of diagnosis is 65.
|22. What does CLL stand for?
|Chronic Lymphocytic Leukemia
|23. What is the typical proliferating cell seen with CLL?
|The characteristic cell is a very monotonous looking lymphocyte (meaning all the lymphocytes in this disorder look the same)
|24. What is Hairy Cell Leukemia?
|This is a very rare form of leukemia that affects the LYMPHOCYTES.
|25. What age group is affected by Hairy Cell Leukemia?
|It is an adult type leukemia (median age 55 years), that has a very slow, insidious onset.
|26. What cell type proliferates in Hairy Cell Leukemia? What does it look like?
|Overall they have a “fried-egg appearance”, oval nucleus, delicate grey cytoplasm with hair-like projections (filipodia), hence the name “hairy cells”.
|27. Does Hairy Cell Leukemia have another name?
|Hairy Cel Leukemia is also known asl Leukemic Reticuloendotheliosis
|28. What does CML stand for?
|Chronic Myelogenous Leukemia
|29. What is the Philadelphia chromosome, and what is its clinical significance in CML?
|It is a part of chromosome 22 that has translocated (moved) to chromosome 9. This requires special testing (reference lab testing) in order to determine this. BUT, the Philadelphia chromosome is present in nearly all cases of CML/CGL/CNLL leukemias.
|30. What is a blast crisis?
|in the bone marrow an excessive numberof cells that can be identified as belonging to the “blast cell stage” of the maturation , blast cells can be found in the peripheral blood and can be derived from the RBCs, WBCs and/or the platelet lineages.
|31. What is the FAB criteria for determining a blast crisis?
|According to the FAB classification, population of the bone marrow and peripheral blood with at least 30% blasts is considered a “blast crisis”.
|What is the WHO criteria for determining a blast crisis?
|According to the WHO classification, population of the bone marrow and peripheral blood with 20% blasts is considered a blast crisis”.
|32. In general, what type of prognosis is associated with a blast crisis? Why?
|very poor prognosis. The more of these types of cells an individual has in their peripheral blood circulation, the poorer their immune status (immunocompromised…), and the greater their chance of becoming gravely ill and/or dying.
|33. What classification of leukemias is a blast crisis associated?
|Blast crises are associated with “acute” leukemias.
|34. Define cytochemistry.
|Cytochemistry is the study of chemical elements found in cells. These elements may be enzymatic (ex: peroxidase) or nonenzymatic (ex: lipids).
|35. Why do clinical laboratories use cytochemical staining techniques?
|Cytochemistry staining is a useful tool in differentiating hematopoietic diseases, especially acute and chronic leukemias.
|36. What are considered acceptable specimens for cytochemical staining techniques?
|The types of specimens that are acceptable for cytochemistry studies (staining) include: smears and imprints made from bone marrow, lymph nodes, spleen, or peripheral
|37. What is the purpose of performing the myeloperoxidase (MPX) staining procedure?
|This stain is useful for differentiating the blasts of acute myeloid leukemia (AML) from acute lymphoblastic leukemia (ALL).
|What is myeloperoxidase and where can MPX be found?
|Myeloperoxidase is an enzyme found in the primary granules of neutrophils, eosinophils and, to a certain extent, monocytes. Lymphocytes do not exhibit MPX activity.
|38. What is the purpose of performing the Sudan Black B (SBB) staining procedure?
|SBB is another useful staining technique for the differentiation of AML from ALL. SBB stains the lipids which are found in the primary and secondary granules of neutrophils and in the lysosomal granules of the monocytes
|39. What is the purpose of performing the Esterase staining procedure?
|esterase activity can be used to distinguish acute leukemias that are myeloid in origin from leukemias that are mostly monocytic in origin, it can differentiate myeloblasts and neutrophilic granulocytes from cells of monocytic origin
|40. What is the purpose of performing the Periodic Acid Schiff (PAS) staining procedure?
|PAS staining may be helpful in the diagnosis of ALLs from the erythroid type of AML.
|41. What is the purpose of performing the Factor VIII Antibodies staining procedure?
|Megakaryoblastic leukemia requires immunocytochemical stains for an accurate diagnosis. Monoclonal or polyclonal antibodies against factor VIII-related antigen give positive results in megakaryoblastic leukemia
|42. What is the purpose of performing the Leukocyte Alkaline Phosphatase (LAP) staining procedure?
|LAP enzyme activity is useful for differentiating CML from a leukomoid reaction.
|43. What is a leukomoid reaction?
|Leukomoid reactions are the immune system’s response to severe infections. LAP enzyme activity is “scored” in PMS and bands only.
|Why does it have a high LAP score?
|Individuals with untreated CML have low LAP scores; individuals with leukomoid reactions have a high LAP score. Severe infection cause the total WBC count to become elevated “shift to the left” (more neutrophils and band/stab)causing high LAP scores
|44. What is the purpose of performing the Acid Phosphatase (Tartrate Resistant) staining procedure?
|this procedure makes the stain a useful diagnostic tool for confirmation of hairy cell leukemia because addition of this reagent inhibits normal granulocytic, lymphocytic, and monocytic enzyme activity, but does not of the abnormal cells
|45. In general, what is an MLT’s responsibility towards identifying and diagnosing leukemia?
|Recognizing an ABNORMALITY and by bringing it to the attention of a supervisor or pathologist.