Manual of Pediatric Hematology and Oncology

Philip Lanzkowsky

• Publisher: Academic Press
• Year: 2005
• ISBN:
  9780123751553
• Edition: 5
• Topic: Biological Sciences
• Subtopic: Biology
• Index: Biological Sciences

Given that there have been considerable advances in the treatment and management of oncologic diseases in children, the fifth edition of this successful clinical manual will be entirely updated to incorporate all current protocols and developments.This edition will be a comprehensive book on patient management, replete with algorithms and flow diagrams on diagnosis and management. Its concise and easy-to-read format will enable readers to make accurate diagnoses and permit them to treat patients without having extensive previous hematologic/oncologic experience. A list of normal values at various ages in children, providing an extremely useful reference for patient management is included.

• Selected for inclusion in Doody's Core Titles 2013, an essential collection development tool for health sciences libraries
• Offers a concise, systematic approach to all pediatric hematologic and oncologic disorders in one reference manual
• Easy-to-read format: multiple tables, charts, and flow-diagrams for diagnosis and management of pediatric hematologic and oncologic disorders
• Clear presentation by practicing clinicians, who are also academic researchers, of recent developments in molecular genetics, cytogenetics, immunology, transplantation, and biochemistry

Chapter 1

Classification and Diagnosis of Anemia in Children

Anemia can be defined as a reduction in hemoglobin concentration, hematocrit, or number of red blood cells per cubic millimeter. The lower limit of the normal range is set at two standard deviations below the mean for age and sex for the normal population.^*

The first step in diagnosis of anemia is to establish whether the abnormality is isolated to a single cell line (red blood cells only) or whether it is part of a multiple cell line abnormality (red cells, white cells and platelets). Abnormalities of two or three cell lines usually indicate one of the following:

• bone marrow involvement, (e.g., aplastic anemia, leukemia), or

• an immunologic disorder (e.g., connective tissue disease or immunoneutropenia, idiopathic thrombocytopenic purpura [ITP] or immune hemolytic anemia singly or in combination) or

• sequestration of cells (e.g., hypersplenism).

Table 1-1 presents an etiologic classification of anemia and the diagnostic features in each case.

Table 1-1 Etiologic Classification and Major Diagnostic Features of Anemia in Children

The blood smear is very helpful in the diagnosis of anemia. It establishes whether the anemia is hypochromic, microcytic, normocytic, macrocytic or shows spezcific morphologic abnormalities suggestive of red cell membrane disorders (e.g., spherocytes, stomatocytosis or elliptocytosis) or hemoglobinopathies (e.g. sickle cell disease, thalassemia).

The mean corpuscular volume (MCV) confirms the findings on the smear with reference to the red cell size, e.g., microcytic (<70 fl), macrocytic (>85 fl) or normocytic (72–79 fl). Figure 1-1 delineates diagnosis of anemia by examination of the smear and Table 1-2 lists the differential diagnostic considerations based on specific red cell morphologic abnormalities. The mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC) are calculated values and generally of less diagnostic value. The MCH usually parallels the MCV. The MCHC is a measure of cellular hydration status. A high value (>35 g/dL) is characteristic of spherocytosis and a low value is commonly associated with iron deficiency.

Figure 1-1 An Approach to the Diagnosis of Anemia by Examination of the Blood Smear. ⁺Spurious macrocytosis (high MCV) may be caused by macroagglutinated red cells (e.g., Mycoplasma pneumonia and autoimmune hemolytic anemia).*Increased number of reticulocytes. **On the basis of increased membrane resulting in an increased membrane/volume ratio. Increased membrane results from exchanges between red cell lipids and altered lipid balance in these conditions.

Table 1-2 Specific Red Cell Morphologic Abnormalities

I. Target cells
Increased surface/volume ratio (generally does not effect red cell survival)

Thalassemic syndromes

Hemoglobinopathies

Hb AC or CC

Hb SS, SC, S-Thal

HbE (heterozygote and homozygote)

HbD

Obstructive liver disease

Postsplenectomy or hyposplenic states

Severe iron deficiency

LCAT deficiency: congenital disorder of lecithin/cholesterol acyltransferase deficiency (corneal opacifications, proteinuria, target cells, moderately severe anemia)

Abetalipoproteinemia

II. Spherocytes
Decreased surface/volume ratio, hyperdense (>MCHC)

Hereditary spherocytosis

ABO ...