Chorioangioma of Placenta- A Case Report

Chorioangioma of Placenta- A Case Report
SK SETHI, U HEMAL, RS SOLANKI, A BHAGRA

Ind J Radiol Imag 2004 14:1:65-66

Key Words: Chorioangioma, Placenta



Chorioangioma constitutes the commonest benign growth of placenta. It consists of a benign angioma arising from chorionic tissue. Chorioangioma is often associated with unfavourable effects on the mother as well as on the fetus. With the advent of gray scale and color flow ultrasonography in prenatal diagnosis these tumours can be easily detected antenatally. We present a case of Choriangioma with associated polyhydramnios and PIH, detected antenatally on gray scale and color flow imaging.


CASE REPORT

A healthy 22year old primigravida presented at 28 weeks of gestation by dates with history suggestive of PIH and severe edema. On admission the physical examination revealed blood pressure of 150/100, respiration rate of 18/min with mild pallor. The patient had evidence of pitting edema of her lower extremities. Her Hb was 8.6gm% and her VDRL was negative. Urine examination revealed evidence of albuminuria.

Ultrasonography revealed a single fetus. Lie was transverse. The biparietel diameter was 74mm and femur length being 51mm both corresponding to a 28 weeks Gestation. Abdominal circumference (240mm) and head circumference (268mm) both corresponded to a 28 weeks period of gestation. There was no craniospinal anomaly. Fetal stomach, kidneys and bladder were normal and the umbilical cord was trivascular. Fetal cardiac four chamber view was normal and there was no pleural effusion or ascites. Polyhydramnios was present. The placenta was on the right lateral wall, was not low lying and was grade II. A well-defined oval echogenic mass measuring 7.5 x 6 cm having echogenicity different from the rest of placenta with focal area of peripheral hypoechogenicity was noted in the central part of the placenta close to the insertion of the umbilical cord causing a lobulated bulge on its fetal side. On color Doppler imaging a central feeding vessel was seen which showed a branching pattern and on pulsed Doppler it showed a pulsatile flow at a rate similar to that of umbilical artery. Patient was admitted and was advised absolute bed rest. The patient delivered vaginally at 34 weeks of gestation. The female infant weighed 1200 gm and had apgar scores of 7 and 7 at one and five minutes respectively. The placenta contained a lobular gray and tan coloured mass measuring 8 x 6 cm. histology showed marked proliferation of small capillaries with intervening loose, fibrous stroma compatible with chorioangioma.

DISCUSSION

Placental chorioangioma is the most common benign tumour of the placenta, occurring in approximately 1% of all pregnancies or in 0.5-1% of all placentas examined at term. It consists of a benign angioma arising from chorionic tissue. Three histological patterns of chorioangiomas have been described: angiomatous, cellular and degenerate. The angiomatous is the most common, with numerous small areas of endothelial tissue, capillaries and blood vessels surrounded by placental stroma. The cellular pattern has abundant endothelial cells within a loose stroma. The degenerate pattern has calcification, necrosis or hyalinization. These lesions are sometimes classified as placental hamartomas rather than true neoplasia. [1]

Most chorioangiomas are of no clinical importance. Those measuring more than 5 cms in diameter may be associated with complications that can affect the mother, the fetus or the neonate. [2]

Of the various reported clinical complications, the correlation of chorioangioma with hydramnios and premature delivery is significant, latter being a sequela of the hydramnios. The association with hydramnios is significantly correlated with the presence of large tumours. Fetal congestive heart failure may develop because of the increased blood flow through the low resistance vascular channels in the chorioangioma acting as an arteriovenous shunt. Other associated complications

being hydrops, anemia, and growth retardation. [3]

Antenatal ultrasound has made diagnosis and follow up possible before delivery. Usual gray scale findings include intraplacental subchorionic location, well-defined circumscription, complex echogenicity different from rest of the placenta, single or multiple tumours and protusion into the amniotic cavity near the insertion of the umbilical cord. [4]

Chorioangiomas show vascular channels in the tumour, which show pulsatile flow in the vascular spaces of the tumour, at the same pulsation rate as the umbilical cord. Color Doppler imaging is important not only for differentiating chorioangioma from other placental lesions but also for confirming that vascular channels in the tumour are continuous with the fetal circulation, thus ruling out other diagnosis such as degenerated myoma, placental teratoma, and incomplete hydatidiform mole. [5,6]

Due to the apparently high fetal death rate associated with large chorioangiomas, early diagnosis is necessary so that fetal surveillance can be instituted. In the present case characterstic gray scale and Doppler findings confirmed the diagnosis of chorioangioma. Doppler studies were particularly useful in confirming the presence of vascular channels with a pulse rate equal to the fetal heart rate.

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