leukemia Flashcards
leukemia
A malignant disorder of the hematopoietic system involving the bone marrow
Cause: Unknown
leukemia risk factors
- Immunodeficiency Disorders
- Genetic Factors (evidence of familial clustering, Down’s Syndrome)
- Exposure to ionizing radiation and chemicals
- Viruses: infection with the human T-cell leukemia virus type 1
- Exposure to Cytotoxic Chemicals (chemo)
leukemia patho
Bone marrow’s control of cell proliferation and maturation is absent or abnormal;
Marrow is replaced by immature and undifferentiated leukocytes, or blast cells
characteristics of normal leukocytes
1.
characteristics of leukemic cells
- > 5% blasts in bone
- Blasts often present in peripheral blood
- Immature
- Multiply continuously
- Provide NO defense against infection
leukemia patho
Proliferation of immature cells occurs and “crowds out” other marrow elements including erythrocytes and thrombocytes, resulting in inhibited growth and function of these cells; As a result “pancytopenia” occurs causing:
- Anemia
- Thrombocytopenia
- Neutropenia
myeloid
(involves cells of “bone marrow” origin) “myelogenous” or “non-lymphocytic” leukemia
lymphocytic
(involves cells of “lymphatic” origin) “Lymphocytic” leukemia
chronic leukemia
the predominant cell is “mature-appearing,” although it does NOT function normally; usually a “cytic” cell
acute leukemia
the predominant cell is “immature,” usually a blast cell
In general, acute leukemias tend to have a rapid onset and progression resulting in
100% mortality within days to months without appropriate treatment
Chronic leukemias tend to have a
more indolent course
leukemic clinical manifestations
- Fatigue, malaise
- Infections*
- Bleeding (bruising, petechiae)
- Fevers
- Night Sweats
- Weight loss
- Anorexia
In addition, with Acute Lymphocytic Leukemia, CNS infiltration seen as:
Headache
Nausea
Vomiting
leukemia diagnostics
CBC: reflects anemia, thrombocytopenia, neutropenia
Differential: indicate main cell type involved
Bone marrow aspiration (or biopsy): typically show a proliferation of blast cells
Lumbar puncture is done to determine leukemic proliferation of CNS
Acute Myelogenous (Non-Lymphocytic) Leukemia AML
- More common in: adolescents and adults over 55 years
- Prognosis better in children
- Associated with: Downs Syndrome
- Greatest risk of: “leukostasis” (stagnation of blood cells due to large number of cells) and “tumor lysis” syndrome
- Complication associated with rapid destruction of WBCs: leads to uric acid, potassium & calcium levels
Tumor Lysis Syndrome
- Signs/sx include: dysrhythmias, confusion, paresthesias
- Hyperuricemia can occur leading to: acute renal failure and need for dialysis
- Treatment: allopurinol
Acute Lymphocytic Leukemia ALL
- Most common type in children, but also prognosis best in children
- CNS infiltration is common
Chronic Myelogenous Leukemia CML
- Age at Onset: 18-30 years and 40-55 years
- May be familial; linked to chromosome abnormality called the: “Philadelphia chromosome” (90% of cases)
- Characterized by a chronic phase (2-7 yrs), followed by a “blast crisis” that resembles acute leukemia
Blast Crisis
- Occurs most commonly in individuals who have: AML, or convert to an AML type of leukemia from CML
- Peripheral Blast counts may range between 50,000-100,000 and result in:
1. Impaired blood flow to vital organs (leukostasis)
2. Leukostasis because large and “sticky” blasts plus arterioles and infiltrate local tissues
Blast Crisis is a medical emergency if the following are present
- Headache (from increased intracranial pressure)
- Altered mental status
- Dyspnea
- Priapism: abnormal, prolonged and sustained erection of penis without sexual stimulation
Blast Crisis management
- Hydrea in large doses destroy myeloblasts
- Corticosteroids destroy lymphoblasts
- Leukopheresis to remove abnormal WBCs from blood
- Radiation therapy to treat brain or sever pulmonary compromise
- Increased doses of chemo
Chronic Lymphocytic Leukemia CLL
- Usually occurs in: adults (>60 years)
- Responsive to oral chemotherapy
- Characterized by proliferation of: small, abnormal B lymphocytes, leading to decreased antibody response
- Cells accumulate in: spleen, lymph nodes
- More common in: men (3X)
Leukemia management (chemo)
- Remission INDUCTION: initial tx of high doses of chemo to “empty” marrow of abnormal elements
- Post-remission therapy: leukemic cell population reduced to undetectable levels
- Consolidation therapy: intensive therapy given to further reduce remaining leukemic cells; may include BMT (bone marrow transplant)
- Maintenance therapy: long-term therapy in moderate dose to “maintain” a disease-free state
