Disorders of Fetal Vascular Development

Abstract

Chorangioma, localized chorangiomatosis, chorangiosis, and diffuse multifocal chorangiomatosis are a group of related, yet distinct vascular lesions found in placental tissue. These lesions are often asymptomatic and underappreciated both grossly and microscopically. Chorangiomas and localized chorangiomatosis have been associated with hypoxia and ischemia and are often found concurrently with disease processes that predispose the placenta to these conditions including preeclampsia, intrauterine growth restriction, and multiple gestations. Small chorangiomas are generally considered clinically insignificant, but when large chorangiomas are present, they have been found to cause polyhydramnios, hydrops fetalis, platelet sequestration, and occasionally fetal death. These can be detected by prenatal ultrasound and embolization can provide a theoretical cure when symptomatic. Chorangiosis is a diffuse increase in terminal villi capillaries and has been associated with diabetes and placental overgrowth syndromes. Multifocal chorangiomatosis is a recently described lesion associated with extreme prematurity (Ͻ32 weeks), congenital malformations, IUGR, delayed villous maturation, avascular villi, and placentomegaly. No treatment currently exists for either chorangiosis or multifocal chorangiomatosis.A 24-year-old white gravida 1 para 0 female at 36 and 2/7 weeks gestation presented for induction of labor secondary to worsening pre-eclampsia and polyhydramnios. Her medical history was significant for 2 separate remote cerebrovascular accidents in 2003 and 2005 requiring continued anticoagulation. Her remaining laboratory evaluation was unremarkable with the exception of group B strep infection treated with ampicillin. Labor failed to progress, and she was taken for a low transverse cesarean section secondary to arrest of dilation the following day. She delivered a viable female infant weighing 2485 g with Apgar scores of 4 and 9. The placenta was submitted for pathologic evaluation.Upon receipt in the gross room, the placenta was noted to weigh 342 g corresponding to a weight less than the tenth percentile for gestational age. The umbilical cord, membranes, fetal surface, and maternal surface were otherwise unremarkable. No gross lesions were noted on sectioning. Microscopically, acute chorioamnionitis was identified with an associated funisitis and chorionic vasculitis. Additionally decidual vasculopathy was seen, which was consistent with the clinical diagnosis of pre-eclampsia. Several small chorangiomas were visualized measuring up to 0.5 cm in greatest dimension. These were not appreciated grossly.