A rare case of giant chorioangioma complicating pregnancy with fetal hydrops

Clinical History

A 32-year-old gravida 3 para 2 woman presented with complaints of dyspnoea, pedal oedema at approx. 33 weeks gestation. She had an over-distended abdomen. She wasn't a known case of diabetes or hypertension. Past pregnancies were uneventful resulting in normal vaginal deliveries. The patient had not undergone any prior ultrasound study for the current gestation.

Imaging Findings

The ultrasound showed well-defined hypoechoic mass measuring approx. 9.5x5.4x7.3 cm attached to the fetal surface of the placenta at its fundal end (Fig.1). Colour Doppler examination showed it to be highly vascular (Fig.2). The fetus showed features of hydrops including pleural effusion, ascites and generalized oedema (skin thickness measured 11mm).
MRI T2- HASTE images showed a well-defined mass lesion measuring 10x5.5x7.5 cm with heterogeneous intensity near the attachment of the umbilical cord at the fundal end of the fetal surface of the placenta. The fetus showed features of hydrops corresponding to ultrasound findings (Fig. 3 a, b, c).
The patient had a preterm vaginal delivery of a stillborn female child weighing 1.8 kg with oedematous and tense skin with reddish hue consistent with hydrops (Fig.4). The placenta showed a single 10x5.5x7.4 cm roughly spherical, reddish brown solid mass weighting approximately 500 grams (Fig.5).
Microscopic examination revealed numerous congested, dilated blood vessels and intervillous fibrin deposition with areas of ischaemic necrosis, characteristic of angiomatous pattern which is seen in the vast majority of chorioangiomas (Fig.6).

Discussion

Chorioangioma term is coined as its components resemble blood vessels and stroma of chorionic villi. Chorioangioma is thought to be hamartoma of primitive chorionic mesenchyme, originally described by Clarke in 1798 [1]. They are benign lesions with no malignant potential [1]. Recurrence of chorioangioma in subsequent pregnancies is rare [4]. They're usually single, small but may present as multiple placental masses of varying sizes or giant tumours measuring > 5 cm.

In cases of small tumours, the fetus is at low risk and the pregnancy proceeds normally. Large tumours are frequently associated with maternal and fetal morbidity, which includes polyhydramnios, due to transudation of fluid caused by the tumour causing mechanical obstruction of blood flow near the cord insertion or placental insufficiency due to shunt mechanism of tumour vasculature [1, 7]. Another striking but rare complication associated is non-immune hydrops fetalis. Large chorioangioma contains vessels which act like arteriovenous shunts causing shunting of blood which alters fetal haemodynamics leading to non-immune hydrops [2, 3].

On grey-scale ultrasound, chorioangioma is a hypo/hyperechoic well-defined mass, classically seen protruding into the amniotic cavity from the fetal surface near the umbilical cord insertion. It is distinct from the placenta, and contains anechoic cystic areas which corresponds to blood vessels or necrotic areas [5]. Spectral-Doppler adds other data that leads to the diagnosis; it demonstrates the same heart rate as the fetus helping to confirm the connection of the mass to the fetal vasculature [1], also differentiating it from other placental tumours like partial hydatidiform mole, teratoma, placental haematoma and uterine submucosal fibroid, which share some of the imaging features. MRI shows a heterogeneous mass with high T2 signal in comparison to the placenta. T1W sequences show a iso/hypointense mass, sometimes with peripheral hyperintensity related to haemorrhage. When acute infarct/degeneration occurs, this may improve the fetal prognosis but, on the other hand, may lead to potential mistakes, such as placental haematoma diagnosis due to lack of demonstrable blood flow.

Expectant management is usually adequate for patients with chorioangioma, as the majority of tumours are asymptomatic. Serial ultrasound monitoring every 6-8weeks is sufficient for small tumours, whereas large tumours require serial examinations every 1–2 weeks. Though prognosis in the later situation is mostly dismal. Interventions include intrauterine transfusions in fetal anaemia, fetoscopic laser ablation of tumour vessels, chemosclerosis, amnioreduction, etc [1, 6].

Ultrasound along with colour Doppler study provides early comprehensive information of the tumour as well as fetal wellbeing. MRI can be used for further evaluation in case of equivocal ultrasound findings, hence appropriate, timely intervention can be planned, reducing maternal and child morbidity.

Differential Diagnosis List

Final Diagnosis

Placental chorioangioma with hydrops fetalis

URL:	https://eurorad.org/case/14610
DOI:	10.1594/EURORAD/CASE.14610
ISSN:	1563-4086