DISCUSSION
Also called ‘’ chorangioma placentae”, placental chorioangioma is the
most frequent non-trophoblastic tumor of the placenta which originates
from the placental chorionic mesenchyme [3]. Placental chorioangioma
accounts for approximately 1% of pregnancies and is predominant in
Caucasian women [4]. The majority of researchers consider
chorioangioma to be a malformation rather than a true neoplasm [4].
Some environmental factors, namely hypoxic stimulus, high altitude, and
vascular growth factors, are possible associations with this tumor’s
occurrence [5]. Large chorioangiomas can induce several
complications in pregnancy such as polyhydramnios, premature labor,
placenta previa, and premature placental separation, leading to high
perinatal morbidity and mortality [6,7]. Other complications of
large chorioangiomas include placental functional inadequacy, mechanical
obstruction of the blood flow, and increased vascular surface area. This
induces increased transudation of fluid, resulting in polyhydramnios
[8]. The pathological complications seen in the neonates include
thrombocytopenia, anemia, stillbirth, edema, non-immune hydrops fetalis,
prematurity, intrauterine growth retardation, or fetal death.
Arteriovenous shunts in large chorioangiomas cause impairment of the
fetal circulation. [9,10]. In the present case, the pregnancy of
this 33-year-old primiparous woman with a large placental chorioangioma
had prematurity as the only adverse effect. Prematurity was probably the
result of the large volume of the placental chorangioma occupying a
significant amount of intrauterine volume and therefore leading to the
induction of early uterine contractions that culminated in the premature
delivery. On ultrasonography, chorioangiomas are well-circumscribed
hypoechoic masses that often protrude into the amniotic cavity from the
fetal surface near the cord insertion. Calcification and necrosis are
occasionally visible [10].
n sonography, the lesion
is well circumscribed and has echogenicity dif-
ferent from that of the rest of the placental tissue.
Large tumors can be of variable shapes, divided
by fibrous septa, and often protrude into the
amniotic cavity from the fetal surface near the
cord insertion
n sonography, the lesion
is well circumscribed and has echogenicity dif-
ferent from that of the rest of the placental tissue.
Large tumors can be of variable shapes, divided
by fibrous septa, and often protrude into the
amniotic cavity from the fetal surface near the
cord insertion
n sonography, the lesion
is well circumscribed and has echogenicity dif-
ferent from that of the rest of the placental tissue.
Large tumors can be of variable shapes, divided
by fibrous septa, and often protrude into the
amniotic cavity from the fetal surface near the
cord insertion
n sonography, the lesion
is well circumscribed and has echogenicity dif-
ferent from that of the rest of the placental tissue.
Large tumors can be of variable shapes, divided
by fibrous septa, and often protrude into the
amniotic cavity from the fetal surface near the
cord insertion In the present case, we used Doppler ultrasound to
monitor fetal wellbeing and circulation; however, despite the presence
of the large chorioangioma, there were no signs of anemia or cardiac
failure. Macroscopically, chorioangiomas are well-circumscribed tumors.
On cut section, they are usually fleshy, congested, and red to tan. We
occasionally note the presence of myxoid, fibroma-like or degenerative
changes. Placental chorioangiomas are often found on the fetal surface
of the placenta with a few cases reported on the maternal surface as
well [6].
The majority of placental chorioangiomas are small measuring less than 5
cm in diameter and are located entirely in the placental parenchyma;
that is why we can be easily miss them if the placenta is not
systematically sliced after delivery [11]. In the present case, the
tumor measured 8.3 x 4.9 cm and was located on the fetal surface near
the umbilical cord insertion with focal cystic change. The definitive
diagnosis of placental chorioangioma relies on histopathological
examination. Histologically, chorioangioma is a benign tumor
proliferation of vessels accompanying connective tissue and an abundant
stromal component. The proportion of vascular and stromal components are
variable, depending upon the dominant histologic type. The vascular
component may comprise either capillaries or sinusoids. Based on
histology, the tumor can be classified as capillary, cavernous,
endotheliomatous, fibrosing, and fibromatous. Such differentiation is
not of clinical concern, since the prognosis depends mainly upon the
size of the tumor. In the current case, the tumor was of the capillary
type [10-11]. There is a rare variant of chorioangioma: “atypical
cellular chorioangioma” characterized by high mitotic activity,
cellularity and abnormal nuclei with proliferating malignant trophoblast
interspersed among proliferating capillaries with large areas of
necrosis [12]. The immunohistochemical study shows a positive
immunostaining of tumor cells for CD31, CD 34, factor VIII, GLUT 1, and
cytokeratin 18. The differential diagnosis of placental chorioangioma
includes chorangiosis and chorangiomatosis. Prognostic factors that
influence the outcome of placental chorioangioma are vascularity and
location of the tumor. Increased vascularity leads to greater shunting
of blood to the physiologic dead space of the tumor, weaning the fetus
of a significant amount of nutrient and air exchange and perhaps
manifesting as intrauterine growth restriction and fetal demise.
Likewise, location is also critical in deciding the pregnancy outcome,
as, in certain reported cases, chorioangiomas as small as 2 cm located
at the outer edge of the placenta have been associated with
complications [8].
Management of chorioangioma depends on its degree of severity. For mild
to moderate types, the treatment is conservative as it was the case for
our patient. For severe cases, there are several management modalities
including in-utero endoscopic devascularization and prenatal treatment
by ultrasound guided interstitial laser therapy. In case of fetal
anemia, in-utero blood transfusion can be done with good outcome. In
case of polyhydramnios, maternal indomethacin therapy or amniocentesis
is useful in management. If complications appear late in pregnancy
delivery is the option of management. [13].
In summary, placental
chorioangioma is associated with an increased risk of complications
influencing the outcome of pregnancy. Despite the existence of
uncomplicated cases, close monitoring and follow up of the patients by
serial ultrasound, surveillance by Doppler, and fetal echocardiography
is highly recommended for these patients. Careful examination of the
placenta, timely antenatal diagnosis, and early intervention are of
paramount importance, to prevent associated morbidity and mortality to
both the fetus and the mother. In the current case, except for
prematurity, there were no clinically significant complications due to
the giant placental chorioangioma measuring 8 cm in diameter.