Massive Subchorionic Thrombohematoma (Breus’ Mole) Associated with Fetal Growth Restriction, Oligohydramnios, and Intrauterine Fetal Death

Abstract

Massive subchorionic thrombohematoma (MST), termed Breus’ mole, is a rare condition in which a large maternal blood clot separates the chorionic plate from the villous chorion. Common complications of MST include fetal growth restriction, preeclampsia, and intrauterine fetal death. Here, we present a case of a 17-year-old Japanese woman referred to our institution at 21 weeks of gestation. Ultrasound examination revealed a large placental mass with mixed high and low echogenicity measuring approximately 7.6 cm in thickness. Doppler examination showed absence of end-diastolic velocity of the umbilical artery. At 22 weeks of gestation, the patient had a stillbirth weighing 138g. The placenta weighed 502 g and was 8 cm thick, and the total blood loss was 270 g. Macroscopic examination revealed that a subchorionic blood clot measuring 12 cm × 5 cm covered a large portion of the placenta with well-defined margins on the fetal surface. Microscopic examination revealed an intervillous hematoma and fibrinous deposits directly beneath the chorionic plate with adjacent compressive effects. Based on these findings, MST was diagnosed. Because MST is rare, it must be considered in the differential diagnosis of parental conditions. Magnetic resonance imaging can be optimal for diagnosing MST when ultrasound diagnosis is difficult.

Doppler evaluation of normal and abnormal placenta

“…It is usually described as a hypoechoic or anechoic area located below the chorion (subchorionic), behind the basal plate (retroplacental) (Figure 18) or below the amnion (subamniotic) (Figure 19a,b) 113,114 . Massive subchorionic hematoma is termed Breus' mole (Figure 19c) 115 . These large hematomas have irregular hypoechoic areas without blood movement.…”

“…Massive subchorionic hematoma is termed Breus' mole (Figure 19c) 115 . These large hematomas have irregular hypoechoic areas without blood movement.…”

Imaging of Placental Pathology

“…On ultrasound the thrombohematoma is visualized as a mass either heterogeneous or homogeneous with mixed high and low echogenicity, distinct from the normal ultrasonic texture of the placental parenchyma. The lesion can also present as placentomegaly [41,87]. MRI and color Doppler are reportedly useful to differentiate "Breus" mole from other placental masses such as placental mesenchymal dysplasia and chorangioma, although no specific findings of "Breus" moles are described [1,78].…”

Fetal survival in pregnancy complicated by massive subchorionic thrombohaematoma

“…Massive subchorionic thrombohaematoma (MST), formerly described as Breus’ mole, is a maternal thrombus greater than 1 cm in thickness that develops between the chorionic plate and villous chorion of the placenta. The thrombus bulges above the chorionic plate often resulting in the compression of umbilical vasculature 1–5. According to the Atlas of Placental Pathology , the thrombus involves at least 25% of the chorionic plate 6.…”

“…MSTs are uncommon, occurring in approximately 1 in 3000 pregnancies 3 7 8. While the underlying aetiology of MST is unclear, several maternal comorbidities have been associated with an increased risk of MSTs including thrombophilia, cardiovascular disease, hypertension, diabetes mellitus and pre-eclampsia 1 2 4 5. Pregnant patients who have received thrombolytic therapy or anticoagulation are also predisposed to MSTs 1 5.…”