Acute Myeloid Leukemia (AML) Overview

Diagnostic Accuracy

• A test with perfect diagnostic accuracy can determine the presence or absence of disease with certainty.
• The diagnostic accuracy of a test is determined by comparing the test's ability to discern true disease from nondisease.
• Patients correctly classified as abnormal are called true-positives (TPs) and those correctly classified as normal are called true-negatives (TNs).
• False results occur because the two populations overlap, and patients incorrectly classified as normal are false-negatives (FNs), and those incorrectly classified as abnormal are false-positives (FPs).

Sensitivity and Specificity

• Sensitivity is the ability of a test to detect disease and is expressed as the proportion of persons with disease in whom the test is positive.
• A test that is 90% sensitive will give positive results in 90% of diseased patients (TP) and negative results in 10% of diseased patients (FN).
• Specificity is the ability to detect the absence of disease and is expressed as the proportion of persons without disease in whom the test is negative.
• A test that is 90% specific will give negative results in 90% of patients without disease (TN) and positive results in 10% of patients without disease (FP).

Predictive Value

• The predictive value of a positive test (PPV) is the probability that a positive test indicates disease.
• PPV is the proportion of persons with a positive test who truly have the disease.

Coulter Principle

• The Coulter principle is a method used to count cells by measuring the changes in electrical resistance caused by cells passing through an aperture.
• Each cell that passes through the aperture displaces an equal volume of conductive fluid, increasing the electrical resistance and creating a voltage pulse.

Conductivity and Electro-Optical Analyzers

• Conductivity is determined using a high-frequency electromagnetic probe that provides information on the cells' internal constituents.
• Electro-optical analyzers use a light-sensitive detector to measure light scattering, which is proportional to the size of the particle.

Iron Deficiency Anemia

• Iron deficiency anemia occurs after total gastrectomy or subtotal gastrectomy.
• Prolonged treatment of peptic ulcer and acid reflux by H2 blockers and acid pump blockers may cause defective iron absorption.
• Causes of malabsorption of iron are extremely rare, except for sprue syndrome.
• Almost all cases of iron deficiency in adult males are due to chronic blood loss.
• Hemorrhagic lesions, medications, and helminthic infections are common causes of iron deficiency in males and postmenopausal females.

Blood Film Characteristics

• In early iron deficiency, the stained blood film shows normochromic normocytic erythrocytes.
• In later stages, the picture is one of microcytosis, anisocytosis, poikilocytosis, and hypochromia.
• Anisocytosis may be identified by automated blood counters as increased red cell distribution width (RDW).

Acute Myeloid Leukemia (AML)

• AML is the most common form of acute leukemia during the first few months of life.
• The onset often resembles acute infection and includes signs of granulocytic insufficiency, with ulcerations of mucous membranes and fever.
• The diagnosis of AML requires the presence of 20% blasts in the marrow or blood.

Acute Lymphoblastic Leukemia

• Acute lymphoblastic leukemia is the most common malignancy of children and adolescents.
• Clinical symptoms include fatigue, fever, and bleeding.
• Anemia is present in precursor B-ALL if clinical manifestations are fully developed, and it is usually normocytic.