Placental Pathology. Afip Atlas of Nontumor Pathology, Vol. 3

Chapter One: Anatomy, Structure, and Function
1.1 Introduction
1.2 Gross and Microscopic Anatomy
1.2.1 Amnion and Membranous Chorion
1.2.2 Umbilical Cord
1.2.3 Chorionic Plate and Stem Villi
1.2.4 Terminal Villous Unit and Interhemal Membrane
1.2.5 Basal Plate and Anchoring Villi
1.2.6 Placental Margin and Membranes
1.3 Developmental Anatomy
1.3.1 Blastocyst Trophectoderm (Days 18 to 20 of Menstrual Cycle)
1.3.2 Nidation and Maternal Capillary Circulation (Days 20 to 28 of Menstrual Cycle)
1.3.3 Chorionic Plate and Body Stalk (4 to 5 Weeks from Last Menstrual Period [LMP])
1.3.4 Villous Stromal Vasculogenesis (5 to 6 Weeks from LMP)
1.3.5 Elaboration of Mesenchymal Villi (6 to 8.5 Weeks from LMP)
1.3.6 Development of Stem Villi (8.5 to 11.5 Weeks from LMP)
1.3.6 Development of Stem Villi (8.5 to 11.5 Weeks from LMP)
1.3.7 Early Implantation and Arterial Plugs (6 to 12 Weeks from LMP)
1.3.8 Late Implantation and Arterial Remodeling (12 to 20 Weeks from LMP)
1.3.9 Membrane Formation and Peripheral Expansion (9 to 18 Weeks from LMP)
1.3.10 Trophoblast Proliferative Units and Placental Growth (13 to 40 Weeks from LMP)
1.3.11 Terminal Villogenesis (22 to 30 Weeks from LMP)
1.4 Functional Anatomy
1.4.1 Fetoplacental Arterial Perfusion
1.4.2 Fetoplacental Venous Return
1.4.3 Maternal Arterial Perfusion/Placental Lobule
1.4.4 Maternal Venous Drainage/Marginal Sinus
1.4.5 Umbilical Cord Dynamics
1.4.6 Membranes and Labor
1.4.7 Syncytiotrophoblast and Maternal Physiology

Chapter 2 Basic Pathways of Prenatal and Peripartum Injury: A Pathogenic Approach to Placental Interpretation
2.1 Introduction
2.2 Primary Adverse Outcomes of Prenatal and Peripartum Injury
2.2.1 Preterm Delivery
2.2.2 Fetal Growth Restriction
2.2.3 Hypoxic-Ischemic Injury
2.3 Placental Lesions
2.3.1 Subcategorization
2.3.2 Physiologic Consequences
2.4 Pathways of Injury

Chapter 3 Clinical Syndromes and Their Pathologic Correlates in the Placenta
3.1 Clinical Diagnoses Based Primarily on Maternal History or Maternal Examination
3.1.1 Pregnancy-Induced Hypertension, Preeclampsia, and Eclampsia
3.1.2 Acute Fatty Liver of Pregnancy
3.1.3 Essential Hypertension
3.1.4 Maternal Thrombophilia (Including Maternal Deep Vein Thromboses, Pulmonary Infarcts, Cerebral Vascular Accidents)
3.1.5 Diabetes Mellitus
3.1.6 Maternal Anemias
3.1.7 Recurrent Spontaneous Abortion (Recurrent Pregnancy Loss, Habitual Abortion)
3.2 Primarily Fetal Conditions
3.2.1 Clinical Chorioamnionitis (Versus Histologic Chorioamnionitis)
3.2.2 Preterm Birth, Preterm Labor, Premature Rupture of Membranes
3.2.3 Post-term Pregnancy
3.2.4 Intrapartum Electronic Fetal Monitoring: Nonreassuring Fetal Heart Rate, Bradycardia, Decelerations
3.2.5 Fetal Growth Restriction, Intrauterine Growth Restriction, and the Small for Gestational Age Newborn
3.2.6 Erythroblastosis: Nucleated Red Blood Cells in the Fetal Circulation of the Placenta
3.2.7 Fetal or Neonatal Thrombocytopenias
3.2.8 Meconium-Stained Amniotic Fluid and the Meconium Aspiration Syndrome
3.2.9 Abnormal Amniotic Fluid Volume

Chapter 4 Disorders of Placental Development
4.1 Introduction
4.2 Disorders of Membrane Development
4.2.1 Placental Membranacea
4.2.2 Circumvallation/Circummargination
4.3 Disorders of Uterine Implantation
4.3.1 Placenta Previa
4.3.2 Placenta Accreta, Increta, Percreta
4.3.3 Superficial Implantation
4.4 Disorders of Placental Migration
4.4.1 Shape Abnormalities
4.4.2 Peripheral Cord Insertion
4.5 Disorders of Villous Development
4.5.1 Distal Villous Hypoplasia with Placental Undergrowth (Peripheral Villous Hypoplasia, "Terminal Villous Deficiency")
4.5.2 Distal Villous Immaturity with Placental Overgrowth ("Delayed Villous Maturation")
4.6 Disorders of Fetal Vascular Development
4.6.1 Chorangioma and Localized Chorangiomatosis
4.6.2 Villous Chorangiosis (Hypercapillarization)
4.6.3 Diffuse Multifocal Chorangiomatosis
4.7 Genetic and Chromosomal Disorders
4.7.1 Metabolic Storage Diseases
4.7.2 Mesenchymal Dysplasia
4.7.3 Chromosomal Abnormalities

Chapter 5 Inflammation and Infection
5.1 Introduction
5.2 Infections
5.2.1 Acute Chorioamnionitis (Histologic)
5.2.2 Subacute Chorioamnionitis
5.2.3 Acute Chorioamnionitis with Peripheral Funisitis
5.2.4 Acute Intervillositis with Intervillous Abscesses
5.2.5 Acute Villitis
5.2.6 Active Chronic Villitis and Intervillositis with Villous Necrosis
5.2.7 Chronic Placentitis, TORCH Type
5.2.8 Chronic Intervillositis with Malarial Pigment
5.2.9 Perinatal Infections with Minimal or No Placental Inflammation
5.3 Idiopathic Inflammatory Lesions
5.3.1 Chronic Villitis (Villitis of Unknown Etiology)
5.3.2 Chronic (Histiocytic) Intervillositis (Massive Chronic Intervillositis)
5.3.3 Chronic Chorioamnionitis
5.3.4 Chronic Deciduitis
5.3.5 Eosinophilic/T-Cell Vasculitis
5.3.6 Chronic Decidual Periarteritis

Chapter 6 Circulatory Problems: Thrombi and Other Vascular Lesions
6.1 Introduction
6.1.1 Circulatory Relationships in the Placenta and the Varied Effects of Intraplacental Clotting
6.2 Maternal Circulation: Thrombi, Hematomas, and Decidual Vascular Lesions
6.2.1 Decidual Vasculopathy: Acute Atherosis and Spiral Artery Thrombi
6.2.2 Infarcts
6.2.3 Intraplacental Hematomas (Intervillous Thrombi) and Massive Subchorial Hematomas
6.2.4 Retroplacental Hematomas, Marginal Hematomas, and Placental Abruption
6.3 Maternal Circulation: Nonvascular Lesions
6.3.1 Massive Perivillous Fibrin Deposition (Gitterinfarcts) and Maternal Floor Infarct
6.4 Fetal Circulation: Thrombi and Hematomas
6.4.1 Fetal Stem Vessel (Large Vessel) Thrombi and Fetal Thrombotic Vasculopathy
6.4.2 Fetal Vascular Narrowing and Increased Umbilical Vascular Resistance
6.4.3 Hemorrhagic Endovasculitis
6.4.4 Endothelial Cushions of Fibrinous Vasculosis
6.5 Fetal Circulation: Other Lesions
6.5.1 Subamnionic Hematoma
6.5.2 Stasis Problems

Chapter 7 Pathology of the Membranes
7.0 Introduction
7.1 Anatomy and Physiology
7.2 Meconium Staining
7.3 Inflammation
7.4 Squamous Metaplasia
7.5 Amnion Nodosum
7.6 Amnionic Bands
7.7 Extramembranous Pregnancy
7.8 Gastroschisis
7.9 Cysts (Subamnionic Fibrin Cysts)

Chapter 8 Umbilical Cord
8.1 Embryonic Development
8.2 Normal Umbilical Cord
8.3 Vestigial Remnants
8.3.1 Allantoic Remnants
8.3.2 Omphalomesenteric Remnants
8.4 Insertion Anomalies
8.4.1 Velamentous Insertion and Membranous Vessels
8.4.2 Marginal Insertion
8.4.3 Furcate Insertion
8.4.4 Tethered Insertion ("Amnionic Webs")
8.5 Cord Length
8.5.1 Short Cord
8.5.2 Long Cord
8.6 Cord Diameter
8.7 Numerical Variation in Umbilical Vessels
8.7.1 Single Umbilical Artery
8.7.2 Supernumerary Vessels
8.8 Focal Lesions
8.8.1 Knots
8.8.2 Abnormal Torsion
8.8.3 Stricture
8.8.4 Hematoma
8.8.5 Hemangioma
8.9 Abnormalities in Umbilical Cord Vessels
8.9.1 Aneurysms
8.9.2 Segmental Thinning
8.9.3 Meconium-Induced Necrosis
8.9.4 Ulceration
8.9.5 Thrombosis
8.9.6 Rupture

Chapter 9 Abortion, Stillbirth, and Intrauterine Fetal Death
9.1 Introduction
9.2 Early Spontaneous Abortion, Products of Conception, and Embryonic Death
9.3 Late Spontaneous Abortion (Miscarriage, Stillbirth, and Intrauterine Fetal Death)

Chapter 10 Fetal and Placental Hydrops
10.1 Introduction
10.2 Immune Hydrops (Erythroblastosis Fetalis, Hemolytic Disease of the Newborn)
10.3 Nonimmune Hydrops
10.3.1 Cardiovascular
10.3.2 Fetal Anemias
10.3.3 Fetal Infections
10.3.4 Pulmonary Lesions and Other Intrathoracic Causes
10.3.5 Major Chromosomal Disorders
10.3.6 Other Congenital Anomalies and Genetic Metabolic Diseases
10.3.7 Fetal Tumors

Chapter 11 Tumor-Like Lesions and Metastatic Neoplasms
11.0 Introduction
11.1 Putative Primary Placental Neoplasms
11.1.1 Hemangioma (Chorangioma)
11.1.2 Intraplacental Leiomyoma
11.2 Teratomas (or Acardiac Twins?)
11.3 Adenoma (Choristoma?)
11.3.1 Hepatocellular Adenoma (Heterotopic Liver)
11.3.2 Heterotopic Adrenal Cortex
11.4 Metastatic Neoplasms
11.4.1 Fetal Primary Tumors Involving the Placenta
11.4.2 Maternal Primary Tumors Involving the Placenta

Chapter 12 Multiple Pregnancy
12.0 Introduction
12.1 Twin Gestation
12.1.1 Zygosity
12.1.2 Frequency and Etiology
12.1.3 Placentation
12.1.4 Umbilical Cord, Chorionic Vascularity, and Placental Mass
12.1.5 Monoamnionic Monochorionic Placentas
12.2 Complications of Multiple Pregnancy
12.2.1 Twin-Twin Transfusion Syndrome
12.2.2 Asymmetric Growth
12.2.3 Intragestational Fetal Loss
12.2.4 Duplication Abnormalities
12.3 Higher Multiple Births

Chapter 13 Examination Technique
13.1 Pathologist-Clinician Relationship
13.2 Approach to the Specific Clinical Scenario
13.3 Stepwise Handling of the Specimen
13.4 Gross Description
13.5 Technique and Rationale for Tissue Sampling
13.6 Multiple Pregnancy
13.7 Alternative Approaches to Placental Examination
13.8 Special Studies

Chapter 14 Diagnostic Ultrasound in Obstetrics
14.1 Introduction
14.2 Ultrasound Imaging of the Placenta and Umbilical Cord
14.3 Ultrasound Imaging of the Fetus
14.3.1 First Trimester Ultrasound Examination
14.3.2 Second and Third Trimester Ultrasound Examination
14.4 Doppler Ultrasound in Assessment of the Growth-Restricted Fetus

Chapter 15 Appendix
15.1 The Value of Placental Measurements