Placental and Obstetric Pathology Flashcards
1
Q
normal placenta - blood flow
A
blood exchange occurs at intervillous spaces, where:
- umbilical arteries delivery oxygenated blood
- which is then picked up by the umbilical vein, and delivered to the fetus
- umbilical veins drain de-oxgenated blood
- which came from the fetus via the umbilical artery
2
Q
normal early term placenta - microscopic morphology
A
- villi are immature & LARGE. they contain a
- core of mesenchyme (where vasculature will eventually develop)
- surrouding thick syncytiotrophoblast & cytotrophoblast layers
3
Q
identify picture & note important features
A
early term normal placenta (6 weeks)
- large villi (V) in the lacunae (L)
- thick syncitio and cyto trophoblast layers
4
Q
identify the picture, not important features
A
early term normal placenta (6 weeks)
- large villi filled with mesenchyme cores (M) surrounded by thick cyto (C) and syncitio (S) trophoblast layers
5
Q
identify the picture, note important features
A
early term normal placenta (6 weeks)
- thick cyto and syncitio trophoblast layers
6
Q
term placenta - microscopic morphology
A
-
smaller, highly branched villi (V)
- presence of vasculature in villi
- in more mature villi, thinning of surrounding layers (cyto and syncitio trophoblast) allows approximation of fetal capillaries (C) to lacunae blood
- presence of vasculature in villi
- presence of synctitial knots: (K) aggregated syncytiotrophoblast nuclei
7
Q
identify the picture, note important features
A
normal term placenta (40 weeks)
-
smaller, highly branched villi
- some villi have vasculature (dark pink)
- presence of syncitial knots (dark blue)
8
Q
identify the picture, note important features
A
normal term placental (40 weeks)
- thinned outer layers that approximate fetal capillaries (C) to maternal blood in lacunae (L)
9
Q
identify the picture, note important features
A
normal term placental (40 weeks)
- presence of vasculature in villi
- presence of syncitial knots (K)
10
Q
identify the picture, not eimportant pictures
A
first trimester chorionic villi
- thick, distinct outer layers (cyto and syncitio trophoblast)
- villi filled with stroma/mesenchyme
11
Q
identify the picture, not important features
A
third trimester chorionic villi
- dense network of villi filled with dilated fetal capillaries
- thinned out surrounding layers (cyto and syncitio trophoblasts)
12
Q
describe a normal umbilical cord
A
- made of 3 vessels
- two umbilical arteries
- one umbilical vein
13
Q
identify the picture, note important features
A
normal umbilical cord
- made of 3 vessels
- two umbilical arteries
- one umbilical vein
14
Q
what are the two types of twin pregnancies?
A
- dizygotic twins: two ovum fertilized
- monozygotic twins: single ovum fertilizted → divides into two
15
Q
what are the variations of twin placentas? what types of twin pregnancies can be seen in each variation?
A
three variations
-
dichorionic diamniotic (fused and separate version)
- can occur with either monozygotic or dizygotic twins
-
monochorionic
-
two types: monochorionic monoamniotic, monochorionic diamniotic
- ONLY occurs with monozygotic twins: single fertilization, is mono vs di amniotic dependent on when embryo split
-
two types: monochorionic monoamniotic, monochorionic diamniotic
16
Q
identify each type of placenta pregnancy
which type of twins can be see in which?
A
-
dichorionic diamniotic (fused and separate version)
- can occur with either
- monozygotic twoms
- dizygotic twins
- can occur with either
-
monochorionic
- ONLY occurs with monozygotic twins: single fertilization, is mono vs di amniotic dependent on when embryo split
17
Q
twin to twin transfusion
- what is the cause / setting?
- what is the implication to the fetus?
A
- seen only in monozygotic twins
-
vascular anastomoses can form between twins. if blood is shunted to one twin preferentially,
- one twin is over-perfused & appears
- plethoric
- polycythemia
- one twin is under-perfused and appears
- pale
- anemic
- one twin is over-perfused & appears
-
vascular anastomoses can form between twins. if blood is shunted to one twin preferentially,
18
Q
identify the picture, note important features
A
twin to twin perfusions
-
vascular anastomoses can form between twins. if blood is shunted to one twin preferentially,
- one twin is over-perfused & appears
- plethoric
- polycythemia
- one twin is under-perfused and appears
- pale
- anemic
- one twin is over-perfused & appears
19
Q
placenta previa?
- definition
- clinical presentation
- variations
A
- condition where placenta implants in the lower uterine segment or cervix
- presentation: in 3rd trimester
- +/- bleeding (worse in certain variations)
- variations:
- complete placenta previa - in which the placenta covers the internal cervical OS - is the most severe
20
Q
placenta accreta
- definition
- clinical presentation
- variations
A
- definition: absence of the decidua (either partial or complete) such that the placenta attaches deeply to the uterine wall
- presentation: severe post-partum hemorrhage that is potentially life threatening
- variations
- placenta increta = placenta attached to uterine muscles
- placenta perrceta = placenta goes completely through uterine wall
21
Q
spontaneous abortion
- definition
- diagnosis
A
- defined as: loss of pregnancy prior to 20 weeks of gestation
- diagnosis: passage of products of conception (chorionic villi) or fetal parts
22
Q
ectopic pregnancy
- most important pre-disposing risk factors
- m/c site of implantation
- clinical presentation
- can progress to?
A
- PID (pelvic inflammatory disease)
- extrauterine fallopian tube (90% of cases) -i.e. “tubal pregnancy”
- clinical presentation - typically follows rupture
- amenorrhea
- abdominal pain
- vaginal bleeding
- can progress to:
- hematosalpinx: blood filled fallopian tube
-
tubal rupture vs spontaneous regression:
- tubal rupture more common: can lead to hemorrhagic shock + signs of acute abdomen
23
Q
A
ruptured fallopian tube
24
Q
what is the most common cause of hematosalpinx?
A
tubal ectopic pregnancy
25
what are the late disorders of pregnancy?
* placental infections
* complete interruption of blood flow thru umbilical cord
* retroplacental hemorrhage
* disruption of fetal vessels
* uteroplacental malperfusion
* pre-eclampsia
* placental previa
26
infections of the placenta?
* typically occur when in pregnancy?
* are caused by?
* can lead to?
* during 3rd trimester (late pregnancy)
* causes:
* **ascending infection thru birth canal (m/c)**
* _almost always bacteria_
* **hematogenous infection** - less common
* d/t TORCH group
27
acute chorioaminiotis
* definition
* morphology
* complications
* placental infection that involves the chorio-amniotic membranes
* morphology
* gross:
* placental membranes **white, pale / green semi opaque**
* amniotic fluid: **cloudy** d/t neutrophils
* microscopic
* **many neutrophils** extending above chorionic membrane
* complications
* if d/t hematogenous infection - can result in **acute villitis** (spread to villi)
28
identify picture, note important features
acute chorioamniotis
* placental membranes **white, pale / green semi opaque**
* amniotic fluid: **cloudy** d/t neutrophils
29
idnentify the picture, note important features
acute chorioamniotis
**many neutrophils** extending above chorionic membrane
30
identify picture, note important features
acute chorioamniotis
**many neutrophils** extending above chorionic membrane
31
identify the picture, note important features
acute chorioamniotis
* presence of **acute villitis,** in this case d/t hematogenous l*isteria* infection
32
pre-eclampsia
* definition
* pathogenesis (contrast to normal pregnancy)
* HTN seen \> 20 weeks of pregnancy
* pathogenesis
* in normal pregnancy:
* endothelial-type trophoblasts invade maternal decidua & “remodel” decidual vessels
* they convert maternal endothelium (small caliber resistance vessels) → fetal endothelial type trophoblastic cells, creating “hybrid vessel” have a **larger capacity** & can _meet circulatory demands_ of late gestation
* in pre-eclampsia
* trophoblasts retain “epithelial” instead of endothelial" type and cannot convert decidual vessels into high capacity vessels, leading to
* hypoxia → release of anti-angiogenic factors → hyperreactivity → vasoconstriction → hypertension
33
pre-eclampsia - classic clinical presentation
seen after 20 weeks (m/c \> 34)
* HTN
* proteinuria
* edema
34
what makes pre-eclampsia more likely to be severe?
presence of a **hypercoagulable state** (coagulation abnormalities)
35
morphologies of pre-eclampsia
* microscopic
* **abnormal decidual vessels with** **fibrinoid necrosis**
* **+/- macrophages**
* premature maturation of placental villi
* gross
* **infarcts**: wedge shaped, pale
* **retroplacental hematomas**
36
identify the picture, note important features
pre-eclampsia microscopic
* **abnormal decidual vessels with fibroid necrosis** (white open arrow) and **adjacent decidual necrosis** (black curved arrow)
* complicated by a recent thrombosis (black open arrow)
37
identify the picture, note the important features
pre-eclampsia microscopic
* fibrinous necrosis in spiral arteries walls (black curved arrow)
* accumulation of foamy macrophages (black open arrows)
38
identify the picture, note important features
pre eclampsia - gross
* placental infarct - off white, firm
39
what are the major complications of pre-eclampsia? describe their presentations.
* eclampsia
* defined by central nervous system involvement:
* headaches
* visual disturbances
* possible seizures → coma
* HELLP syndrome (especially predisposed by a hyper-coagulable state)
* H- hemolytic anemia
* EL - elevated liver enzymes
* LP - low platelets
* low platelets
40
hydratiform moles
* definition / cause
* subtypes
* are a type of gestational trophoblastic disease (group of diseases characterized by proliferation of placenta tissue) involving a fertilization defect.
* subtypes
* complete mole: feralization of an egg that lost its chromosomes
* incomplete mole: fertilization of egg by two sperms
41
complete hydratiform mole
* cause
* karyotype
* morphology
* associated risks
* cause: fertilization of an egg that has lost its female chromosomes
* karyotype:
* **46XX 90% of the time** male X chromosome doubled _(androgenesis)_, therefore genetical material entirely paternally derived
* 46-XY the rest
* morphology
* **“grape-like” structures** consisting of edematous polyp
* **trophoblastic proliferation involving _all or most villi_.**
* villi are
* are ENLARGED
* have a _scalloped shape_
* often have _cistern_: central cavitation
* **empty embryo (not fetal tissue identified)**
* associated risks:
* **persistent hydratiform mole**
* **invasive mole**
* **choriocarcinoma**
42
incomplete hydratiform mole
* cause
* karyotype
* morphology
* associated risks
* cause: fertilization of an **egg with two sperm**
* karotype: **triploid (69-XXY**) \> tetraploid (92-XXXY)
* morphology:
* only **SOME of villi are affected** (focal trophoblastic hyperplasia). these villi are
* enlarged
* cisterns seen
* **can contain trophoblast psueodinclusions**
* **fetal tissue identified**
* associated risks
* **increased risk of persistent mole**
* NO increased risk of choriocarcinoma
43
identify the picture, note important features
complete hydratiform mole - gross
* **“grape-like” structures** consisting of edematous polyp
* **all villi markedly swollen**
44
identify the picture, note important features
complete hydratiform mole
* **“grape-like” structures** consisting of edematous polyp
* **all villi markedly swollen**
45
identify picture, note important features
compllete hydratiform mole
huge central cistern
46
identify the picture, note important features
complete hydratiform mole
## Footnote
marked, circumferential trophoblast proliferation (i.e., every villi effected)
47
identify the picture, note important features
complete hydratiform mole
* large villi with scalloping
* marked edema
48
identify the picture, not important features
partial hydratiform mole
* partial scalloping
* isolated trophoblastic inclusion
49
identify picture, note important features
partial hydratiform mole
* trophoblast pseudoinclusions
50
identify picture, note important features
partial hydratiform mole
* trophoblastic proliferation of one villi surrounded by severe unaffected, smaller villi
* flattened central cistern
51
invasive mole
* definition
* clinical features
* morphology
* a mole that penetrates/perforates the myometrium
* is ALWAYS associated with persistently elevated hCG
* morphology
* gross - hemorrhagic mass invading thickness of endometrium
* microscopic - invasion of myometrium by villi covered by proliferating trophoblasts
52
placental choriocarcinoma
* etiology
* clinical features
* morphology
* sequelae
* comes from
* **complete hydratiform moles (50%)**
* previous abortions
* normal pregnancies
* clinical features
* incidence is 1 /20,000-30,000
* presentation
* **irregular vaginal spotting** of a **bloody, brown fluid**
* **high propensity of metastasis**
* **m/c site = lungs (50%)**. next =
* vagina (30%)
* bone, liver, bone, kidney
* morphology
* gross **- soft, fleshy yellow-white tumo**r with _large areas of necrosis/extensive hemorrhage_
* microscopic-
* **DOES NOT PRODUCE CHORIONIC VILLI**. consists entirely of proliferating cyto and synctio trophoblasts
* invading myometrium
53
identify the picture, note important features
invasive mole - microscopic
* villi covered in proliferating trophoblast **are invading the myometrium**
54
identify the picture, note important features
invasive mole - gross
* **hemorrhagic mass** has invaded half the **thickness of the myometrium**
55
identify the picture, note important features
placnetal choriocarcinoma
* extensive necrosis / hemorrhage extending into myometrium
56
identify the picture, note important features
placental choriocarcinoma - microscopic
* markedly enlarged trophoblastic nuclei (arrow) but no villi formation
57
compare and contrast incomplete and complete moles in terms of
* karyotype
* effect on hCG
* presence of fetal tissue
* associated risks
complete
* 46-XX (90%)
* always lead to an increase in hCG
* NO fetal tissue present
* can lead to persistent mole, invasive mole, choriocarcinoma
incomplete
* 46-XXY
* doesnt always lead to increase in hGF
* fetal tissue present
* can lead to persistent mole
