Chronic lymphocytic leukemia (CLL) is the most common leukemia in the Western hemisphere and may be complicated in several important ways:

Smudge cells may be seen on peripheral blood smear in CLL. Hypogammaglobulinemia is a hallmark of CLL.

Chronic myelogenous leukemia (CML) is characterized by BCR/ABL fusion [translocation of chromosomes 9 and 22 t(9;22)], also known as the Philadelphia chromosome.

Imatinib mesylate was developed as a specific inhibitor of the BCR/ABL tyrosine kinase. In patients refractory to, or intolerant of, interferon, imatinib results in a near 100% hematologic remission and at least a 50% cytogenetic remission. Second- and third-generation tyrosine kinase inhibitors are now available as well.

Patients who present with the clinical features of CML, but lack detectable BCR/ABL, often have another myeloproliferative disorder, such as myelofibrosis or chronic myelomonocytic leukemia.

Acute myeloid leukemia (AML) is defined by the presence of ≥20% myeloblasts in the peripheral blood or bone marrow. Most important prognostic indicators include age, cytogenetics, and molecular genetics.

Treatment of AML remains 3 days of an anthracycline and 7 days of cytarabine. Consolidation chemotherapy is indicated in good-risk cytogenetics. However, allogeneic stem cell transplantation has benefit in those with poor-risk cytogenetics.

Elderly AML patients receive dose-reduced chemotherapy regimens.

Acute promyelocytic leukemia (APL) is a unique subtype of AML. It is characterized by coagulopathy in the form of disseminated intravascular coagulation.

APL is extremely sensitive to all-trans retinoic acid (ATRA), anthracycline, and arsenic trioxide. Cure rates are high in APL.

The treatment of Hodgkin’s disease often uses alkylating agents. Myelodysplastic syndromes (MDS) and AML are the most common secondary malignancies associated with the treatment of Hodgkin’s disease.

MDS are characterized by ineffective hematopoiesis, bone marrow failure, peripheral blood cytopenias, and reduced survival. Increased age and exposure to alkylating agents/topoisomerase II inhibitors, and ionizing radiation are risk factors for MDS.

MDS may be classified as indolent or aggressive (lower or higher risk). Allogeneic stem cell transplant, the only potentially curative approach to MDS, is a realistic option for only about 5% to 10% of patients.

Acute lymphoblastic leukemia (ALL) is divided into two major categories: precursor lymphoid neoplasms and mature lymphoid neoplasms. Most ALL treatment for adults follows the basic strategy of induction, consolidation-intensification, CNS prophylaxis, and maintenance therapy. Successful adult chemotherapy regimens have been modeled after pediatric regimens.

The incidence of infection increases with more profound and prolonged neutropenia, particularly as the absolute neutrophil count falls to <500/µL.

In febrile neutropenia, prompt antibiotic administration is critical. The initial empiric antibiotic should be broad-spectrum enough to cover a wide variety of organisms, including Pseudomonas aeruginosa.

Tumor lysis syndrome (TLS) occurs when blasts are broken down rapidly into the bloodstream, either spontaneously or following antineoplastic therapy—most common in rapidly proliferative hematology malignancies, such as AML, ALL, and Burkitt’s lymphoma.

TLS is associated with sudden development of hyperkalemia, hyperuricemia, hyperphosphatemia, hypocalcemia, and increased serum lactate dehydrogenase levels. Patients should be started on allopurinol and hydration with intravenous fluids.