Focal aneurysmal dilatation of subchorionic vessels simulating chorioangioma

Placental mesenchymal dysplasia

CONTEXT

Placental mesenchymal dysplasia is characterized by placentomegaly and may be mistaken for molar pregnancy both clinically and macroscopically because of the presence of "grapelike vesicles." It may be associated with a completely normal fetus, a fetus with growth restriction, or a fetus with features of Beckwith-Wiedemann syndrome.

OBJECTIVE

To review the etiology, molecular pathology, gross and microscopic features, clinical presentation, complications, and differential diagnosis of placental mesenchymal dysplasia.

DATA SOURCES

The PubMed and the Medline databases were systematically searched for articles between 1970 and 2006. The following keywords were used: placental mesenchymal dysplasia, mesenchymal hyperplasia, molar pregnancy, pseudomolar pregnancy, Beckwith-Wiedemann syndrome, and placentomegaly. Relevant references from review articles were also searched.

CONCLUSIONS

Placental mesenchymal dysplasia should be considered in the differential diagnosis when the ultrasonographic findings show a cystic placenta. Close attention should be paid to fetal morphology for early recognition of fetal complications and to prevent unnecessary termination of pregnancy in cases associated with a normal fetus.

Suspected involvement of the X chromosome in placental mesenchymal dysplasia

So far, 46 cases of placental mesenchymal dysplasia have been reported worldwide. We encountered 15 cases of placental mesenchymal dysplasia (PMD) including 7 cases delivered in our hospital. The incidence of PMD in our hospital was therefore, 7/30,758 (0.02%). The PMD had a peculiar appearance. In the gross findings, large placenta with intestine-like dilatation of the vessels on the fetal side was reported. Microscopically, cistern-like dilatation of the stem villi, fetal artery thrombosis, and villous hemorrhage were reported. However, we believe most of these findings are secondary rather than the primary of mesenchymal dysplasia. Therefore, we investigated 15 other cases of mesenchymal dysplasia, and found including vascular abnormality of the stem, intermediate and terminal villi in all case of PMD. The abnormality was observed in the vessels of the periphery of the stem villi and their vessel walls were thin and appeared weak. The intermediate villous vessels were unusual, tangled. The terminal villous abnormalities showed chorangiosis and stromal hyperplasia. These findings are mesenchymal dysplasia origin. Moreover, PMD showed female-predominant. 14/15 was female among our cases, We discuss the relationship between mesenchymal dysplasia and the X chromosome in this paper.

Fetal anemia, thrombocytopenia, dilated umbilical vein, and cardiomegaly due to a voluminous placental chorioangioma. A case report

We report a case of voluminous placental chorioangioma diagnosed by ultrasound and color Doppler imaging during the 20th week of pregnancy. The size of the tumor was enlarging progressively (up to 10 cm in the 32nd week), and during this time the signs of fetal intrauterine volume overload and blood cell consumption, such as cardiomegaly, umbilical vein dilation, hydramnios, anemia, and thrombocytopenia, were observed. In the 32nd week of pregnancy, the signs of uteroplacental insufficiency and fetal hypoxia appeared; therefore, the pregnancy was terminated by cesarean section, and a female infant weighing 1,870 g was delivered. She was discharged, fully recovered, after 48 days. Histopathological examination of the placental tumor showed a benign, vascular-type chorioangioma.

Alcoholization: the choice of intrauterine treatment for chorioangioma

Chorioangioma is a vascular tumor of the placenta. Most are small and asymptomatic, whereas the large tumors are clinically significant and often associated with polyhydramnios and fetal heart failure. To prevent fetal loss from these complications, many interventions have been proposed, including intrauterine transfusion in anemic cases and fetoscopic surgery to ablate the feeding vessels. The case presented herein had large chorioangiomas, 8 and 4cm in diameter, associated with polyhydramnios and early signs of hydrops fetalis, diagnosed at 27 weeks gestation. After extensive counseling, we performed alcohol ablation of the feeding vessel of the larger tumor. Signs of fetal heart failure and hydrops fetalis disappeared dramatically. The pregnancy was extended for 2 weeks, followed by premature rupture of the membranes and spontaneous labor at 32 weeks gestation and a surviving female baby, weighing 1360g, was delivered uneventfully. This preliminary experience suggests that alcoholization may be one of the best choices for this condition due to its high efficacy, simplicity, safety and very low cost. To our knowledge, this is the first report using alcoholization for the treatment of hydrops fetalis secondary to chorioangioma.

Prenatal diagnosis of solid placental masses: the value of color flow imaging

OBJECTIVES

To determine the value of color flow imaging in the prenatal differentiation of solid placental masses protruding from the fetal surface of the placenta.

METHODS

Seven pregnancies in which a large solid mass was seen on the fetal surface of the placenta were prospectively studied. Color flow imaging was used to identify vessels within the mass and the prenatal ultrasound finding correlated with placental pathology.

RESULTS

Postpartum examination of the placenta revealed four cases of chorioangioma, two cases of subchorionic thrombohematoma and one case of subamniotic hematoma. Prenatal ultrasound using color flow imaging correctly identified all cases of placental chorioangioma by the demonstration of blood flow within the mass. Conversely, absence of blood flow signals was invariably documented in both cases of subchorionic thrombohematoma and in the single case of subamniotic hematoma. Among the four cases of chorioangioma, two developed complications requiring delivery. No complications were noted in cases of avascular placental masses in this series.

CONCLUSIONS

Color Doppler ultrasound plays an important role in the prenatal evaluation of solid placental masses. This technique allows the identification of those cases at increased risk of pregnancy complications which need close monitoring throughout gestation.