Acute Myelogenous Leukemia (AML) Quiz

Acute Myelogenous Leukemia (AML)

• AML is a neoplasm of myelogenous progenitor cells
• Accounts for 80% of adult acute leukemias
• Risk factors: exposure to radiation, myeloproliferative syndromes, Down's syndrome, and chemotherapy (e.g., alkylating agents)
• Response to therapy is not as favorable as in acute lymphoblastic leukemia
• Acute promyelocytic leukemia (APL) is a variant of AML, characterized by t(15;17), often presents with pancytopenia
• Treatment: all-trans retinoic acid (ATRA) without delay, along with concurrent chemotherapy once the diagnosis is confirmed

Acute Lymphoblastic Leukemia (ALL)

• ALL is a neoplasm of early lymphocytic precursors
• Histology reveals a predominance of lymphoblasts
• Most common malignancy in children under 15 in the United States
• Most responsive to therapy
• Poor prognostic indicators: age > 9, WBC > 105/mm3, CNS involvement
• Clinical features:
  • Anemia and associated symptoms
  • Increased risk of bacterial infections due to neutropenia
  • Abnormal mucosal or cutaneous bleeding due to thrombocytopenia
  • Splenomegaly, hepatomegaly, lymphadenopathy
  • Bone and joint pain due to invasion of periosteum
  • CNS involvement, diffuse or focal neurologic dysfunction
  • Testicular involvement, anterior mediastinal mass (T-cell ALL)
  • Skin nodules (AML)

Chronic Lymphocytic Leukemia (CLL)

• CLL is a neoplasm of mature B cells
• Indolent NHL B-cell neoplasm, small lymphocytic leukemia
• Clinical features:
  • Usually asymptomatic at time of diagnosis
  • Generalized painless lymphadenopathy, splenomegaly
  • Frequent respiratory or skin infections due to immune deficiency
  • Fatigue, weight loss, pallor, skin rashes, easy bruising, bone tenderness, and/or abdominal pain in advanced disease
• Diagnosis:
  • Laboratory findings: CBC, WBC: 50,000 to 200,000, anemia, thrombocytopenia, and neutropenia are common
  • Peripheral blood smear: absolute lymphocytosis, presence of smudge cells
  • Flow cytometry of peripheral blood: clonal population of B cells
  • Bone marrow biopsy: presence of infiltrating leukemic cells in bone marrow
• Treatment:
  • Chemotherapy has little effect on overall survival, but is given for symptomatic relief and reduction of infection
  • Patients are often observed until symptoms develop
  • Prognosis is variable depending on the number of lymph node sites involved and the presence or absence of anemia/thrombocytopenia

Chronic Myeloid Leukemia (CML)

• Neoplastic, clonal proliferation of myeloid stem cells
• Patients are usually older than 40 years of age
• CML follows an indolent course for many years before it transforms to acute leukemia
• The end point of the disease course is usually an acute phase (or blast crisis), which is an accelerated phase of blast and promyelocyte production

Hodgkin's Lymphoma

• Bimodal age distribution: 15-30 years of age and >50 years of age
• Lymph node histology divides the disease into four subtypes:
  • Lymphocyte predominance, nodular sclerosis, mixed cellularity, and lymphocyte depletion
• Diagnosis:
  • Biopsy of lymph node or other affected tissue
  • CXR: may reveal hilar or mediastinal adenopathy
  • CT scan: to determine extent of disease spread and patient's response to treatment
  • Serum LDH and b2 microglobulin are indirect indicators of tumor burden
  • Other tests: alkaline phosphatase, liver function tests, bilirubin, CBC, serum electrolytes, and renal function tests
  • Bone marrow biopsy
• Treatment:
  • Varies depending on the stage and subtype of NHL
  • Indolent forms of NHL are not curable, but have a 5-year survival rate of 75%
  • Intermediate and high-grade NHLs may be curable with aggressive treatments