Intro to Hematologic Malignancies Flashcards
What is a leukemia?
A leukemia is a malignancy of hematopoietic cells where the chief manifestation is involvement of the blood and marrow
What is a lymphoma?
A lymphoma is a malignancy or hematopoietic cells, derived from lymphocytes or their precursors where the chief manifestation is a solid mass
What sort of cells may result in malignancies?
All cells from blasts to plasma cells may give rise to malignancies
What are high grade leukemias and lymphomas?
High grade lymphomas may present as a rapidly enlarging mass. High grade (acute) leukemias may present with very high WBC counts and near replacement of the normal cells in marrow and blood.
What characterizes acute leukemias?
Acute leukemias result from a hematopoietic neoplasm that progresses rapidly. Patients typically have low production of normal blood cells, causing anemias, thrombocytopenias, and low neutrophils. Acute leukemias are rapidly fatal without therapy. Frequently are blast cells, and may display Auer rods
What two conditions that present differently are actually identical?
CLL and SLL (small lymphocytes lymphoma) are genetically and phenotypically identical. Termed CLL/SLL
What characterizes chronic leukemias?
CML and CLL. Slower progressing leukemias. Normal WBCs, but too many. Increased WBC, insidious onset, often asymptomatic, long natural course of disease, with small risk of transformation to higher grade disease.
What are low grade leukemias and lymphomas?
A low grade lymphoma may present as only mildly enlarged lymph nodes. Low grade leukemias (chronic) are often noted incidentally by an increased WBC.
How are causative mutations found in hemalignancies?
Larger mutations and translocations can be found by cytogenetic studies including karyotyping and FISH. More recently discovered mutations are frequently point mutations requiring PCR to detect.
What are six general etiological themes regarding hematologic malignancies?
Chromosomal Translocations, Viruses (EBV, HTLV-1, KSV/HHV-8, not currently known to play a role in myeloid neoplasms), Inherited immunodeficiencies, conditions of genomic instability (ataxia-telangiectasia), Radiation exposure, and certain chemotherapies.
How does the WHO define Myeloid malignancies?
Myeloid malignancies are defined as malignancies arising from mature or immature members of the granulocytic, monocytic, erythroid, megakarycytic, and mast cell lineages.
How does the WHO define Lymphoid malignancies?
Lymphoid malignancies are those arising from the B-cell, T-cell, or NK cell lineages.
What are the five parameters used by the WHO to classify hematological malignancies?
1) Microscopic appearance of the cells. 2) Histological growth pattern of the malignant cells in the marrow, lymph nodes, or other tissue. 3) Presence or absence of specific cytological or molecular findings. 4) Relative amount of malignant cells present in the blood or marrow. 5) Presence or absence of certain cell surface, cytoplasmic, or nuclear markers.
What characterizes acute leukemias and what tools are used to differentiate and categorize them?
Acute leukemias are characterized by the rapid accumulation of (usually) immature cells in the marrow which displace the normal cells , causing cytopenias. They can be further categorized by microscopy (morphological appearances) or, if the cells are generic appearing blasts, by flow cytometry and immunohistochemistry. The majority can then be categorized as ALLs or AMLs.
What is MDS?
Myelodysplastic Syndrome is a group of conditions where a clonal population derived from a hematopoietic stem cell takes over the marrow and is not capable of producing normal cells of one or more lineages. This results in severely decreased peripheral blood counts. MDS has a high rate of conversion to AML and may be considered a precursor, but is often fatal in its own right due to decreased blood cells.
