Hematology and Coagulation

A Comprehensive Review for Board Preparation, Certification and Clinical Practice

Amer Wahed, Amitava Dasgupta

• Publisher: Elsevier
• Year: 2015
• eBook ISBN: 9780128003817
• Topic: Biological Sciences
• Subtopic: Biochemistry
• Index: Biological Sciences

Hematology and Coagulation is a clear and easy-to-read presentation of core topics and detailed case studies that illustrate the application of hematopathology knowledge to everyday patient care. In order to be successful, as well as to pass the American Board of Pathology examination, all pathology residents must have a good command of hematopathology, including the challenging topics of hematology and coagulation. Hematology and Coagulation meets this challenge head on.This basic primer offers practical examples of how things function in the hematopathology clinic as well as useful lists, sample questions, and a bullet-point format ideal for quick pre-board review. This book provides only the most clinically relevant examples designed to educate senior medical students, residents and fellows and "refresh" the knowledge base, without overwhelming students, residents, and clinicians.- Takes a practical and easy-to-read approach to understanding hematology and coagulation at an appropriate level for both board preparation as well as a professional refresher course- Covers all important clinical information found in larger textbooks in a more succinct and easy-to-understand manner- Covers essential concepts in hematopathology in such a way that fellows and clinicians understand the methods without having to become specialists in the field

Chapter 1

Complete Blood Count and Peripheral Smear Examination

This chapter discusses accurate and appropriate interpretation of complete blood counts (CBCs) as well as the reviewing of peripheral smears. Such review is important not only to detect benign hematological abnormalities but to detect hematological malignancies. Technical aspects of hematology analyzers are also discussed, As are common challenges in CBC interpretation and peripheral smear review examination.

Keywords

Complete blood count; peripheral smear; hematological abnormalities; hematological malignancies; technical aspect

Contents

1.1 Introduction 1

1.2 Analysis of Various Parameters by Hematology Analyzers 1

1.2.1 RBC Count and Hemoglobin Measurement 3

1.2.2 Hematocrit, Red Blood Cell Distribution Width, Mean Corpuscular Volume, Mean Corpuscular Hemoglobin, and Mean Corpuscular Hemoglobin Concentration 4

1.2.3 Reticulocyte Count 5

1.2.4 WBC Count and Differential 5

1.2.5 Platelet Count, Mean Platelet Volume, and Platelet Differential Width 5

1.3 Review of Peripheral Smear 6

1.3.1 Red Cell Variations and Inclusions 7

1.3.2 WBC Morphology 7

1.3.3 Platelets 8

1.4 Special Situations with CBC and Peripheral Smear Examination 10

1.4.1 Splenic Atrophy or Postsplenectomy 10

1.4.2 Microangiopathic Hemolysis 10

1.4.3 Leukoerythroblastic Blood Picture 10

1.4.4 Parasites, Microorganisms, and Nonhematopoietic Cells in the Peripheral Blood 11

1.4.5 Buffy Coat Preparation 12

Key Points 12

References 14

1.1 Introduction

A complete blood count (CBC) is one of the most common laboratory tests ordered by clinicians. Even for a routine health checkup of a healthy person, CBC is ordered to ensure there is no underlying disease when the individual may be asymptomatic. Tefferi et al. noted that at the Mayo Clinic in Rochester, Minnesota, approximately 10–20% of CBC results are reported as abnormal. Common abnormalities associated with abnormal CBC include anemia, thrombocytopenia, leukemia, polycythemia, thrombocytosis, and leukocytosis [1]. For CBC analysis, the specimen must be collected in an ethylene diamine tetraacetic acid (EDTA) tube (lavender or purple top).

CBC consists of numbers that are printed out from the hematology analyzer. In addition, the printout contains graphs and “flags.” Flags are essentially messages provided by the analyzer to the interpreting person that certain abnormalities may be present. For example, an analyzer may flag that blasts are present. Therefore, a review of blood smear slides is required to verify the presence of blasts. To make a meaningful interpretation of the peripheral smear, a review of not only the CBC printout but also the patient’s electronic medical records must be conducted. CBC parameters that are printed from an automated hematology analyzer are red blood cell (RBC)-related numbers, white blood cell (WBC)-related numbers, and platelet-related numbers (Box 1.1).

Box 1.1

Various Parameters Printed by a Hematology Analyzer Following CBC Analysis

Red Blood Cell (RBC)-Related Numbers

RBC count

Hemoglobin level

Hematocrit

Red cell differential width (RDW)

Mean corpuscular volume (MCV)

Mean corpuscular hemoglobin (MCH)

Mean corpuscular hemoglobin concentration (MCHC)

Reticulocyte count

White Blood Cell (WBC)-Related Numbers

Total WBC count corrected

Total WBC count uncorrected

WBC differential

Absolute count of each type of WBC

Platelet-Related Numbers

Platelet count

Mean platelet volume (MPV)

Platelet differential width (PDW)

1.2 Analysis of Various Parameters by Hematology Analyzers

Modern hematology analyzers are capable of counting as well as determining the size of various circulating blood cells in blood, including RBCs, WBCs, and platelets [2]. One such instrument, the Beckman–Coulter analyzer, generates an electrical pulse when a blood cell passes through the analyzer channel, which consists of a small aperture surrounded by electrodes. Each electrical pulse represents an individual cell, and pulse height indicates the cell volume. Modern hematology analyzers are also capable of multimodal assessment of cell size and cell count, thus providing additional information regarding various categories of WBCs, such as neutrophils, lymphocytes, monocytes, eosinophils, and basophils.

The following are examples of various channels in a hematology analyzer:

Channel for red cells (and also platelets...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• Dedication
• Preface
• Chapter 1. Complete Blood Count and Peripheral Smear Examination
• Chapter 2. Bone Marrow Examination and Interpretation
• Chapter 3. Red Blood Cell Disorders
• Chapter 4. Hemoglobinopathies and Thalassemias
• Chapter 5. Benign White Blood Cell and Platelet Disorders
• Chapter 6. Myeloid Neoplasms
• Chapter 7. Monoclonal Gammopathy and Its Detection
• Chapter 8. Application of Flow Cytometry in the Diagnosis of Hematological Disorders
• Chapter 9. Cytogenetic Abnormalities and Hematologic Neoplasms
• Chapter 10. Benign Lymph Nodes
• Chapter 11. B Cell Lymphomas
• Chapter 12. T Cell and Natural Killer Cell Lymphomas
• Chapter 13. Hodgkin Lymphoma
• Chapter 14. Lymphoproliferative Disorders Associated with Immune Deficiencies and Histiocytic and Dendritic Cell Neoplasms
• Chapter 15. Essentials of Coagulation
• Chapter 16. Thrombophilias and Their Detection
• Chapter 17. Sources of Errors in Hematology and Coagulation
• Index