Unit II Flashcards
(98 cards)
Hematologic malignancies share the common characteristic that they arise from ______ ____ that came from a transformed cell of marrow derivation
clonal populations
leukemia
malignancy of hematopoetic cells, where the chief manifestation is involvement of the blood and marrow
lymphoma
a malignancy of hematopoetic cells, derived from lymphocytes or their precursors, which presents primarily as a solid mass
Extramedullary myeloid tumor
(granulocytic sarcoma)-a malignancy of hemaotpoetic cells, derived from myeloid cells or their precursors (granulocytes, monocytes, etc) which presents primarily as a solid mass
Persistant findings of chromosomal translocation are important to note because:
1) their persistence allows them to be used as diagnostic markers for certain hematological malignancies
2) Their persistent presence suggests they play critical role in development of the hematological malignancy they are associated with
What might be one explanation of the frequent translocations in lymphocytes?
genomic instability during immunoglobulin/T cell receptor rearrangement in B and T cells
3 viruses known to play a role in lymphomas:
1) Epstein-Barr virus (EBV)
2) Human T cell leukemia virus-1 (HTLV-1)
3) Kaposi sarcoma herpesvirus/Human herpesvirus-8 (KSV/HHV-8)
Acute Leukemias
Usually due to rapid accumulation of (usually) immature cells in the marrow. They often replace many normal marrow cells, resulting in cytopenias. Most can be classified as Acute Myeloid Leukemia or Acute Lymphoblastic Leukemia
Myelodysplastic syndromes
a group of conditions where a clonal population derived from a neoplastic HSC takes over marrow, and is NOT capable of making normal blood cells in one or more lineages (dysplasia). Categorized by falling peripheral blood cell counts. Often MDS can progress to AML
Myeloproliferative Neoplasms
neoplastic clonal proliferations of the marrow where the clone makes normal functioning blood cells, usually in multiple lineages, but makes too many of them in one or more lineages.
What causes the signs and symptoms of acute leukemia?
When immature leukemic cells accumulate in the bone marrow, they displace normal hematopoetic elements.
Chromosomal abnormalities may be found in __% of AML patients and ___% of ALL patients
95
90
Different types of AML:
granulocytic, monocytic, erythroid, megakaryocytic
Risk factors for acute leukemia
- previous chemo, esp. with DNA alkylating agents and topoisomerase II inhibitors
- tobaccos smoke
- ionizing radiation
- benzene exposure
- Syndromes: Down, Bloom, Fanconi anemia, ataxia-telangiectasia
Signs and symptoms of acute leukemia
fatigue, malaise, dyspnea, easy bruisability, weight loss, bone pain, anemia and pallor, thrombocytopenia, hemorrhage, ecchymoses, petechia, fundal hemorrhage, fever and infection, adenopathy, hepatosplenomegaly, mediastinal mass
Most common age for ALL
75% of cases of ALL occur in children under age 6
In order to diagnose ALL, lymphoblasts must be identified. This is done with :
immunophenotyping
Immunophenotyping markers to diagnose ALL
CD34-marks immature lymphobasts, but often expressed by myloblasts.
TdT-expressed by immature lymphocytes only
Does B-ALL or T-ALL account for more cases of ALL?
B-ALL accounts for 80-85% of all cases of ALL
B lymphoblasts express Be lineage antigens:
CD19, CD22, CD79a
usually do not express mature B cell markers such as CD20
Recurrent cytogenetic abnormalities of B-ALL
1) t(9,22) BCR-ABL1
2) t of 11q23, MLL
3) t(12;21) ETV6-RUNX1
Rank the prognoses of the most common B-ALL cytogenetic abnormalities
t(12;21) > t 11q23 MLL > t(9;22)
What age group does T-ALL occur in most commonly?
adolescents and young adults and males more than females
How does T-ALL often present?
with a component of lymphoblastic lymphoma (T-LBL), often manifesting as a large mediastinal mass