Peds Flashcards
Define malformations, disruptions, deformations and give and example of each
Malformation: Primary error of morphogenesis in which there is an intrinsically abnormal developmental process. Example congenital heart disease
Disruption: Secondary destruction of organ or body region that was previously normal. Example amniotic band
Deformation: Extrinsic disturbance of development rather than intrinsic error of morphogenesis. Example clubfoot due to oligohydramnios
Define hamartoma, choristoma, heterotopia, ectopia, sinus, fistula
Define sequence and malformation syndrome and give an example of each
Sequence - cascade of anomalies initiated by a single aberration. Example Potter’s sequence
Malformation syndrome: group of congenital anomalies that may be pathologically related but do not result from a single aberration. Example Down’s syndrome
Describe Potter squence
Chronic oligohydramnnios causes fetal compression.
Flattened facies
Small chest circumference with pulmonary hypoplasia
Talipes equinovarus/clubfeet
Hip dislocation
Amnion nodosum is characteristic
Pulmonary atresia
Oligo
Twisted skin/facies
Extremity deform
Renal agen
Define agenesis, aplasia, atresia, hypoplasia, hyperplasia, hypertrophy, hypotrophy
Agenesis: absence of organ primordium
Aplasia: Failure of organ primordium to develop beyond its primitive form
Atresia: abnormal absence of closure of an organ orifice or passage
Hypoplasia - under of incomplete development or decreased size due to decreased number of cells
Hyperplasia - increased size of an organ due to increased number of cells
Hypertrophy - increased size of organ due to increase size of cells
Hypotrophy - decreased organ size due to decreased cell size
Reasons to examine a placenta
Obtain information useful in management of mother, neonate, or future pregnancies
Identify pathology
Assess neonatal risk for sequelae
Exclude retained placenta
Explain adverse outcomes
How to differentiate between an artery and vein on chorionic plate at gross
Arteries cross over veins
Common causes of large placenta
Twin pregnancy
Placental edema
Maternal DM
Chronic intrauterine infection
Severe fetal anemia
Rh incompatibility
Fetal alpha-thal major
Placental chorangiomas
Metabolic storage disease
Common causes of small placenta
IUGR
Chromosomal anomalies
Intrauterine infection
Maternal vascular palperfusion
Gross and histologic findings of placenta infarct
Colour depends on age of infarct
Wedge-shaped but vili immediately beneath chorionic plate spared
Coagulative necrosis of group of vili
Intervillous spaces patent early but later filled by fibrin and obliterated
Adjacent villi have increase syncytial knots
Broad categories of organisms transmitted to fetuses by cervicovaginal (ascending route)
Mostly bacterial but some viral (eg HSV2)
Mechanism of ascending intrauterine infection
Inhalation of infected amniotic fluid
Passing through infected birth canal during delivery
Chronological sequence of placental histologic findings in ascending intrauterine infection
Acute subchorionitis
Acute chorionitis
Acute chorioamnionitis
Acute chorioamnionitis with acute chorionic vasculitis, umbilical cord vasculitis, and funisitis
What broad categories of maternal blood-borne infections can be transmitted to the fetus via the placenta? What is the main histological feature?
Infections - parasitic and viral, few bacterial (syphilis, listeria)
Histology - chronic villitis, multifocal
- plasma cells suggest CMV
- Listerosis = multifocal acute villitis with microabscesses
Types of twin placentation
Dichorionic diamniotic, 2 discs or 1 fused disc
Monochorionic diamniotic
MonoMono
Gross findings of twin placentation
1 or 2 discs
Dividing membrane - thick and opaque (dichorionic) or thin and translucent (monochorionic)
Monochorionic - look for twin to twin transfusion syndrome (arteriovenous vascular anastamosis)
Histology of dividing membrane of monochorionic vs dichorionic placenta
Monochorionic - no chorionic tissue in dividing membrane
Dichorionic - amnion chorion amnion
Zygosity determination
Twins different sex - dizygotic
Placenta monochorionic - monozygotic
Placenta dichorionic - 80% dizygotic
Features of chronic histiocytic intervillositis
Infiltrate of histiocyte-predominant mononuclear cells in intervillous space
Represents abnormal cell-mediated immune response at maternal-fetal surface
Associated with adverse fetal outcome, including first and second trimester miscarriage and impaired growth
25% recurrence rate
Sometimes with massive perivillous fibrin deposition
Massive perivillous fibrin deposition vs maternal floor infarct
Massive perivillous fibrin deposition - >50% of placenta, tends to be thick, firm, pale
Maternal floor infarction - layer of fibrin deposition surrounding basal villi with other villi spared
Both associated with second trimester fetal loss, IUGR, and chronic histiocytic intervillositis, tend to recur
Gross and microscopic features and clinical significance of chorangiomas
Gross - well demarcatd, firm round nodules, may be in placental slices or bulging/pedunculated on surface. Often dark red
Microscopic - capillary-sized vessels and scanty stroma, may have foci of infarction
Clinical significance - small ones are insignificany, large ones may cause polyhydramnios, obstruction, fetal cardiomegaly or anemia
Gross and microscopic features and clinical significance of velamentous cord insertion
Gross - umbilical cord inserts into and traverses the free membranes
Micro - chorionic vessels seen in membrane roll
Clinical significance - susceptible to tearing during labor and delivery, associated with SGA babies
Gross and microscopic features and clinical significance of circumvallate placenta
Gross - placental membranes fold in on themselves forming a raised white ring at the junction of extraplacental membranes and fetal surface. Can be complete or partial
Micro - fibrin and infarcted chorionic villi folded over surface with double membranes
clinical significance - Increased frequency of low birth weight, perinatal mortality, antepartum bleeding, premature labour, fetal hypoxia
Clinical manifestations of preeclampsia
Pregnancy-induced hypertension and proteinuria develop after 20GW
Subcutaneous edema
Epigastric pain/liver tenderness common in preeclampsia pts with HELLP syndrome
Placental gross and histologic findings in preeclampsia
Small placental size
Multiple infarcts due to maternal vascular malperfusion
Decidual arteriopathy
Accelerated villous maturation
Why do cytogenetic analysis of abortus tissue
~50% of early pregnancy losses have chromosomal anomalies
Analysis may provide insight for parents regarding recurrence
Usually only medically indicated when 3 or more pregnancy losses
Limitations of cytogenetic analysis for abortus tissues
Fetal tissue may be contaminated by maternal cells
Needs viable tissue for karyotyping as that requires tissue culture - recently largely replaced by RAD
Pathologist’s role in cytogenetic analysis for abortus tissue
Examine to select appropriate tissue
Can submit representative tissue to confirm viability
Value of performing autopsies on macerated stillborn fetuses
Demonstrate presence or absence of malformations which may suggest an inheritable condition
Demonstrate present or absence of infection
Presence or absence of intrauterine stress - thymic involution, mec aspiration, pseudofollicular changes in adrenal cortex
Determine approx age of fetus, IUGR
Status of fetus when infection started - eg presence of fetal response indicates fetus was alive
Predict outcome of future pregnancies
Inheritable condition
Infection
Fetal stress
Status of fetus visavis inf
Estimation of duration of fetal death before delivery
Degree of maceration
- mild 0-1 day: red skin with slippage and peeling
- mod 2-7day: extensive peeling and red serous fluid in chest and abdomen, calvarial slippage
- severe >14d: yellow-brown liver +/- mummification
Presence of diffuse avascular villi and obliteration of stem vessels >2 weeks
Common autopsy findings in intrauterine/neonatal death in trisomy 13
Patau syndrome
- microphthalmia, iris coloboma, incomplete forebrain
- microcephaly, cleft lip/palate, cyclopia and proboscis
- polydactyly
- VSD, PDA, ASD
- SGA, inguinal hernia, single umbilical artery
Common autopsy findings in intrauterine/neonatal death in trisomy 18
Edward syndrome
- small mouth, micrognathia, low set ears
- overlapped fingers, short dorsiflexed toe
- valvular abnormalities, ASD, VSD, PDA
- SGA, short sternum
Common autopsy findings in intrauterine/neonatal death in trisomy 21
Down syndrome
- open operculum
- flat facies, oblique palpebral fissues, epicanthal folds
- simian crease, short metacarpals and phalanges, sandal deformity
- AVSD, VSD
- SGA
Common autopsy findings in intrauterine/neonatal death in monosomy X
Turner syndrome
- nuchal cystic hygroma
- marked edema or dorsal surfaces
- Coarctation of aorta
- SGA, generalized hydrops, normal ovaries at birth
Genetic abnormalities in turner syndrom
50% of cases - complete monosomy X
50% of cases - partial monosomy X or mosaics
Manifestations of turner syndrome in adolescents
Short stature
hypogonadism
streak ovaries
failure to develop 2ary sex characteristics
short webbed neck
broad chest with widely spaced nipples
congenital heart disease
melanocytic nevi
Genetic abnormalities in down syndrome
95% T21 (meiotic nondisjunction)
3% translocations
2% mosaics
Main autopsy findings in congenital herpes
Microcephaly, hydrocephaly, microphthalmia
Main autopsy findings in congenital CMV
Microcephaly, hydrocephaly, microphthalmia
necrotizing meningoencaphalitis
arterial and periventricular calcs
giant cell hepatitis, cholangitis
viral inclusions in lungs, kidneys
Main autopsy findings in Congenital toxoplasmosis
Mostly asymptomatic
Severe: hydrocephaly, microcephaly, intracranial calcs, hepatosplenomegaly, jaundice, chorioretinitis
Visible organisms in multiple organs and tissues
Impact of timing of exposure to teratogens on severity of fetal anomalies
0-3wk GA: severe insult will result in abortion, less severe no apparent effect
3-9wk GA: organogenesis = very susceptible
>9wk: organogenesis complete, already formed organs susceptible to growth retardation and damage
Well documented tertogens
Thalidomide
Folate antagonists
Ethanol
Androgenic hormones
Warfarin
Retinoid acid
Valproic acid