Taber's Medical Dictionary

leukemia, leucemia

(loo-kē′mē-ă)

[leuko- + -emia]
Any of a class of hematological malignancies of bone marrow cells in which immortal clones of immature blood cells multiply at the expense of normal blood cells. As normal blood cells are depleted from the body, anemia, infection, hemorrhage, or death result. The leukemias are categorized as chronic or acute; by the cell type from which they originate; and by the genetic, chromosomal, or growth factor aberration present in the malignant cells.
Chronic leukemias, which have a relatively slow course, include chronic lymphocytic (CLL), chronic myelogenous or granulocytic (CML), and hairy cell leukemia (a subtype of CLL). Median survival in these illnesses is about 4 yr.

Acute leukemias include acute lymphocytic (ALL) and acute myeloid (myelogenous) (AML) leukemia. If untreated, these diseases are fatal within weeks or months. Each of these types of leukemia is discussed in subentries, below.
SEE: Nursing Diagnoses Appendix


SYMPTOMS AND SIGNS
All the different molecular events leading to the development of unchecked cellular reproduction in the leukemias result from genetic or chromosomal lesions in blood-forming cells. Duplications of genetic material (hyperdiploidy), loss of genetic information (hypodiploidy), inactivation of genes that normally suppress tumor development, chromosomal translocations, and the release of abnormal fusion proteins can all cause leukemia. These genetic lesions in turn can be produced by viruses, ionizing radiation, chemotherapeutic drugs, and toxic chemicals. Rarely, leukemias are caused by familial genetic syndromes, e.g., ataxia telangiectasia, Bloom syndrome, or Fanconi syndrome.

SYMPTOMS AND SIGNS
Clinical findings such as anemia, fatigue, lethargy, fever, and bone and joint pain may be present. Physical findings include combinations of pallor, petechiae, or purpura; mucous membrane bleeding; enlarged liver, spleen, and kidneys; and tenderness over the sternum and other bones.

DIAGNOSIS
Microscopic examination of peripheral blood and specimens of bone marrow are used to establish the diagnosis. These studies are followed by cytochemical and cytogenetic studies of abnormal cells found in the marrow or the peripheral blood to confirm the diagnosis with special stains and chromosomal analysis. Leukemic cells can also be identified by flow cytometry and immunocytochemistry, which rely on antibodies binding to and helping to identify malignant cells. The spread of leukemias to internal organs, e.g., the brain, the kidneys, or the lungs, may be evaluated with imaging tests, e.g., MRI studies, CT scans, or ultrasound.

TREATMENT
Chemotherapy, bone marrow transplantation, or both are used to treat leukemias. Regimens are devised regularly and are tailored to specific illnesses. Treatment is often given in several phases, with a period of induction chemotherapy to induce remission by completely eliminating leukemic cells from the bone marrow, followed by consolidation and maintenance phases. This multiphase treatment is designed to further deplete malignant cells from the bone marrow and to achieve complete cure.

PATIENT CARE
Patient care measures focus on eradicating the illness; managing complications; minimizing the effects of chemotherapy; preserving veins (often an indwelling port is inserted to administer chemotherapy); and providing comfort, education, and psychological support. The specific needs of patients (many of whom are children) and their families must be considered. Instruction is provided about drugs the patient will receive, including any adverse reactions and measures that will be taken to prevent or alleviate these effects. Prescribed chemotherapy is administered with special precautions when indicated for infusion and drug disposal. If the chemotherapy causes weight loss or anorexia, nutritional guidance is provided. Oral, skin, and rectal care must be meticulous, e.g., the nurse must thoroughly clean the skin before all invasive procedures, inspect the patient for perirectal erosions, use strict aseptic technique when starting an intravenous line, and change sets, i.e., intravenous tubing and associated equipment, according to chemotherapeutic protocols. Ports are irrigated according to agency protocol. If the patient is receiving intrathecal chemotherapy, the lumbar puncture site is checked frequently for bleeding or oozing. The patient and family are taught to recognize signs of infection (fevers, chills, sore throat, cough, urinary difficulties) and are urged to report these to the oncologist or hematologist promptly. To prevent infection in neutropenic patients, strict hand hygiene protocols, special diets, and (in hospitalized patients) laminar airflow or other reverse isolation measures are instituted. The patient is monitored for bleeding. If bleeding occurs, compresses are applied and the bleeding site is elevated. Transfusions of platelets and other blood cells are often needed. Complications associated with specific chemotherapeutic regimens, e.g., hair loss, nausea and vomiting, anemia, neutropenia, and low platelets, are explained to the patient, along with management strategies that will be employed. Prescribed analgesics are administered as needed, and noninvasive pain relief techniques and comfort measures (e.g., position changes, cutaneous stimulation, distraction, relaxation breathing, and imagery) may be used. Gentle oral hygiene measures and protective skin care are explained. Fluid intake should be increased to eliminate chemotherapy metabolites, and the patient advised to void more frequently to prevent cystitis. Dietary fiber is important, and stool softeners may be used to ensure normal bowel movements. Antidiarrheals usually control diarrhea, but the patient should be monitored for signs of dehydration. Fatigue is an anticipated adverse effect of treatment; therefore the patient is encouraged to alternate activity with rest periods and to obtain assistance with daily activities as necessary. Reproductive issues should be discussed with the patient. Patient care routines and visiting times should be flexible when hospitalization is required. The patient and family are encouraged to participate in care as much as possible. Referrals are made to social service agencies, home health care agencies, and support groups. If the patient does not respond to treatment and has reached the terminal phase of the disease, supportive nursing, palliative care, or hospice care should be discussed sensitively with patients and their caregivers.

acute lymphoblastic leukemia

SEE: Acute lymphocytic leukemia.

acute lymphocytic leukemia

ABBR: ALL A hematological malignancy marked by the unchecked multiplication of immature lymphoid cells in the bone marrow, blood, and body tissues. It is rapidly fatal if left untreated.
SYN: acute lymphoblastic leukemia

ACUTE LYMPHOCYTIC LEUKEMIA Peripheral blood smear ; leukemia

INCIDENCE
In 2013, the National Cancer Institute estimated that about 6,100 Americans would be diagnosed with ALL and that more than 1,400 would die of the disease.

CAUSES
Any of a wide range of acquired or congenital chromosomal abnormalities can cause ALL, including lesions that result in the release of excess growth factors from cells and those that cause the loss of cancer-suppressing genes.

SYMPTOMS AND SIGNS
Fatigue, lethargy, bleeding, bone and joint pain, and a predisposition to fever and infection are characteristic of ALL and other leukemias.

DIAGNOSIS
The disease is suggested by the presence of abnormalities on the complete blood count or peripheral blood smear and is confirmed by immunophenotyping.

TREATMENT
In childhood, ALL induction chemotherapy often begins with steroids, vinca alkaloids, and asparaginase. This is followed, after bone marrow recovery, by consolidation chemotherapy with multidrug regimens, including high-dose methotrexate. Maintenance therapies, which may last 2 years or longer, include methotrexate, mercaptopurines, and other cytotoxic agents. Prophylaxis against central nervous system disease is accomplished by intrathecal drug administration. In referral hospitals, allogeneic stem cell transplantation is sometimes used for refractory disease. About 90% of treated children achieve remission. The 5-year survival of children with ALL is about 85%. Adult ALL is much less responsive to therapy; only about a third of adult patients are cured. In both childhood and adult ALL, allopurinol and hydration precede induction chemotherapy to prevent hyperuricemia caused by tumor lysis.

IMPACT ON HEALTH
Late complications of therapy are not uncommon.

acute myelogenous leukemia

ABBR: AML SEE: Acute myeloid leukemia.

acute myeloid leukemia

ABBR: AML Any of a group of hematological malignancies in which neoplastic cells develop from myeloid, monocytic, erythrocytic, or megakaryocytic precursors. AML is four times more common in adults than acute lymphocytic leukemia (ALL). In 2013, the National Cancer Institute estimated about 14,600 Americans would be diagnosed with AML, and that the disease would cause 10,400 deaths. It occasionally follows a myelodysplastic disorder or aplastic anemia and sometimes occurs as a consequence of a familial disorder of fragile chromosomes, e.g., Fanconi syndrome.
All forms of AML are marked by neoplastic replacement of normal bone marrow and circulation of blasts (immature cells) in the peripheral blood. Anemia and thrombocytopenia commonly occur. The central nervous system and other organs are occasionally invaded. Complete remissions occur in approximately 65% of treated patients; responses to treatment lasting 5 years are achieved in 15% to 25% of treated patients.
SYN: acute myelogenous leukemia; acute nonlymphocytic leukemia

CAUSES
Genetic and chromosomal aberrations, such as are found in other leukemias, are characteristic.

SYMPTOMS AND SIGNS
Exertional fatigue as a result of anemia, bleeding due to thrombocytopenia, and infections due to a lack of normal white blood cells are common.

TREATMENT
Cytotoxic chemotherapies, with an induction phase followed by consolidation, are used. Typically, cytosine arabinoside and an anthracycline are used during induction for AML. Allogeneic bone marrow transplantation is used when a matching donor is available; stem cell transplantation is an option for some patients with specific cytogenetic abnormalities.

acute nonlymphocytic leukemia

ABBR: ANLL SEE: Acute myeloid leukemia.

aleukemic leukemia

SEE: Leukemia cutis.

chronic lymphocytic leukemia

ABBR: CLL A malignancy in which abnormal lymphocytes (usually B cells) proliferate and infiltrate body tissues, often causing lymph node enlargement and immune dysfunction. Infectious complications are common. Median life expectancy is about 4 years. The timing of treatment and the prognosis in CLL depend on the stage of the disease. Staging includes such factors as the number of abnormal lymphocytes in the bloodstream, how quickly they double, and the presence of lymphadenopathy, organomegaly, or cytopenias.

CHRONIC LYMPHOCYTIC LEUKEMIA Peripheral blood smear

INCIDENCE
Chronic lymphocytic leukemia is the most common leukemia in industrialized nations. It usually occurs in people (older men) above age 60. Its incidence rises to 20 cases per 100,000 in people over 80. In 2013, the A National Cancer Institute estimated that about 15,700 people would be diagnosed with CLL and that 4,600 would die of the disease.

TREATMENT
Patients with advanced stages of CLL are often treated with chlorambucil, fludarabine, or other cytotoxic agents, often with a monoclonal antibody to enhance response. Patients with early-stage disease are not usually given therapy.

chronic myelogenous leukemia

ABBR: CML SEE: Chronic myeloid leukemia.

chronic myeloid leukemia

ABBR: CML A hematological malignancy marked by a sustained increase in the number of granulocytes, splenic enlargement, and a specific cytogenetic anomaly (the Philadelphia chromosome) in the bone marrow of more than 90% of patients.
SYN: chronic myelogenous leukemia

INCIDENCE
The disease affects three people per 100,000.

CAUSES
CML results from a translocation of genetic material (the bcr-abl gene) between chromosomes 9 and 22. The translocation results in the production of an abnormal tyrosine kinase that makes affected cells immortal.

SYMPTOMS AND SIGNS
CML often is diagnosed in asymptomatic patients who are found to have an unexplained leukocytosis when their complete blood counts are checked. Subsequent evaluation, including bone marrow aspiration and biopsy with cytogenetic analysis, reveal the Philadelphia chromosome. The course of the disease has three phases: a chronic one in which blood counts are relatively easy to control with medications; an accelerated phase in which granulocyte counts become more resistant to chemotherapy; and a “blast” crisis, which resembles acute leukemia. Median survival is about 4 years. It generally occurs between ages 40 and 50, affecting slightly more men than women (4,600 adults in the U.S. in 2005).

TREATMENT
Imatinib mesylate (a drug that blocks an abnormal kinase made by Philadelphia chromosome positive CML cells) effectively reduces the number of tumor cells in the chronic phase of CML to normal in nearly 90% of patients. An alternative is stem cell transplantation.

IMPACT ON HEALTH
In 2013 the National Cancer Institute estimated that 5900 people would be diagnosed with CML and that approx 600 would die of the disease.

leukemia cutis

An invasion of the dermis and subcutaneous fat by leukemic cells. The invasion often happens before these cells proliferate in the bone marrow or are detectable in the peripheral blood. The cells may cause several different types of skin rashes, including blue nodules (giving the skin a “blueberry muffin” appearance), papules, plaques, and ulcers.
SYN: aleukemic l

hairy cell leukemia

ABBR: HCL A chronic, low-grade hematological malignancy of abnormally shaped B lymphocytes (hairy cells). The disease is marked by pancytopenia and splenomegaly. Median survival in untreated patients is about 5 years. The disease is rare, being only 1% to 2% of all leukemias. The median age of patients is 50 years; men are affected more commonly than women by a 4-to-1 ratio.

HAIRY CELL LEUKEMIA Bone marrow aspirate

SYMPTOMS AND SIGNS
Weight loss, hypermetabolism, infectious complications, and abdominal discomfort due to splenic enlargement are common.

TREATMENT
Cladribine, pentostatin, interferon alfa, and rituximab (a monoclonal antibody) are representative chemotherapeutic options.


LYMPHOCYTES IN HAIRY CELL LEUKEMIA (Orig. mag. ×640)

mixed-lineage leukemia

ABBR: MLL An aggressive, primarily childhood leukemia caused by the translocation of a gene from chromosome 11 to a region that overproduces fusion proteins.