Introduction to Hematologic Malignancies Flashcards
List the main manners in which hematologic malignancies may manifest, and explain how these may overlap.
Leukemia: chief manifestation is involvement of blood and marrow, many times includes disease s of lymphoid and myeloid cells, both mature and immature.
Lymphoma: heme malignancy, derived from lymphocytes and their precursors, which chiefly manifests as a solid mass. (may be nodal, extranodal, or both)
Extramedullary myeloid tumor/granulocytic sarcoma: a heme malignancy, composed of myeloid cells or their precursors (e.g. granulocytes, monocytes, myeloblasts), present as a solid mass.
All malignancies have a presence of a clonal malignant population of cells derived from a transformed cell of marrow derivation.
Many hematopoietic neoplasms contain both a leukemic and a lymphomatous component.
High Grade vs. Low grade Lymphomas
High grade lymphoma: Rapidly enlarging mass
Low grade lymphoma: Midly enlarged lymph nodes
Acute leukemia vs Chronic leukemia
Acute leukemia: Very high white blood cell count, with near normal replacement of normal cells in the marrow and blood. Rapidly fatal if not treated.
Chronic leukemia: Indious onset, often no sx at time of dx. Increased WBC
Recall the biological reason that many lymphomas contain balanced translocations involving the immunoglobulin and T cell receptor genes.
The transformation of a hematopoeitic cell to a malignant cell is thought to require multiple genomic insults.
Relate the importance of specific recurrent translocations in certain hematologic malignancies in regard to the clinical care of patients.
The persistance of these genomic abnormalities allows their use as a diagnositic marker for certain heme malignancies.
List 3 viruses known to have oncogenic roles in some cases of lymphoma.
Epstein-Barr virus (EBV)
Human T cell leukemia virus-1 (HTLV-1)
Kaposi sarcoma herpesvirus/Human herpesvirus 8 (KSV/HHV-8)
Contrast the incedences of leukemia and lymphoma in adult populations versus childhood populations.
Non hodgkin lympphoma is more common than leukemia in adults (no. 6 and no. 10, respectively)
Leukemia is more common than lymphoma in children (no.1 and no.3 respectively)
Classification of hematologic malignancy
Myeloid: resemble cells of granulocytic, monocytic, erythroid, megakaryocytic, and/or mast cell lineages.
Lymphoid: resemble cells of B cell, T cell, and NK cell lineages.
Other: resemble histocytes, dendritic cells, and Langerhans cells.
Data used to define different types of heme malignancies.
- Microscopic appearance of malignant cells
- histologic growth patterns of the malignant cells in the marrow, lymph node, or other tissue
- presence of absence of specific cytogenic findings or moelecular findings
- relative amount of malignant cells present in the marrow or blood
- presence or absence of certain cell surface markers, cytoplasmic markers, and/or nuclear markers.
Basic functional categorization of hematologic malignancies
Acute leukemias: rapidly growing malignancy, usually with a block in maturation resulting in the accumulation of immature cells in the marrow, often replacing normal marrow cells, are often accumulating in the blood as well. Can be myeloid or lymphoid.
Myelodysplastic syndrome: group of conditions where the marrow is overtaken by a neoplastic clone that is incapable of making normal effective blood cells in one or more myeloid lineages (dysplasia). Usually characterized by persistently low blood cell counts in one or more lineages.
Myeloproliferative neoplasms: marrow is overtaken by a neoplastic clone that makes normal functioning myeloid cells, usually in multiple lineages, but makes too many of them in one or more lineages.
Classical hodgkin lymphoma: derived from B cells
Non-hodgkin lymphoma: all the different malignancies of mature lymphocytes, excluding classical Hodgkin lymphoma and malignancies of plasma cells. Divided into B cells NHLs (more common) and T cell/NK NHLs (less common)
Plasma Cell neoplasms: includes MGUS, plasmacytoma, and multiple myeloma
Other: histiocytoses, dendritic cell tumors, and other rare entities.
