Placental pathology casebook. Chorangiosis of the placenta increases the probability of perinatal mortality

Focal Chorangiosis: Does It Have Clinical and Pathologic Significance?

INTRODUCTION

Chorangiosis is a proliferation of capillaries in terminal chorionic villi and is considered to be a marker for hypoxia and poor clinical outcome. Not all cases with hypervascular villi meet the generally accepted diagnostic criteria as reported by Altshuler. Our aim was to evaluate cases with villous hypervascularity that do not meet the diagnosis of chorangiosis, in which increased vascularity was present in a significant portion of the villous tissue but was not a diffuse process, which we call focal chorangiosis, to ascertain whether there were clinical or pathologic associations.

MATERIALS AND METHODS

A total of 175 placentas with the finding of focal chorangiosis and 176 maternal age- and gestational age-matched controls were evaluated retrospectively. We defined focal chorangiosis as villous hypervascularity that did not meet criteria for a diagnosis of chorangiosis, but in which there was involvement of at least 50% of villi on at least 2 of 3 slides of placental tissue or involvement of all the villi on 1 slide. In these focal areas, the criteria of 10 capillaries in each of 10 villi in ten 10× microscopic fields were required.

RESULTS

We found that focal chorangiosis is associated with a decrease in Apgar scores, increased placental weight, fetal vascular thrombosis (fetal vascular malperfusion), umbilical cord abnormalities, increased fetal nucleated red blood cells, villous dysmaturity, and increased rate of vaginal delivery.

DISCUSSION

Many of these associations are shared with chorangiosis as traditionally defined, suggesting that focal chorangiosis is a significant finding that should be reported.

Chorangiosis of Chorionic Villi: What Does It Really Mean?

Chorangiosis has been regarded as a result of low-grade placental hypoxia associated with pregnancy risk factors and abnormal outcomes. It is unknown whether these are a consequence of chorangiosis itself or of associated other placental pathology.Context.—

To prove that chorangiosis itself does not portend an increased risk for pregnancy unless associated with other placental pathology.Objective.—

This retrospective statistical study analyzes 1231 consecutive placentas with diffuse or focal hypervascularity of chorionic villi: 328 with preuterine pattern of chronic hypoxic placental injury (group 1), 297 with uterine type of chronic hypoxic placental injury (group 2), and 606 cases with chorangiosis (group 3) not fulfilling the inclusion criteria for groups 1 or 2.Design.—

Group 2, with 33 cases of chorangiosis (11.1%), featured 10 and 11 statistically significant highest percentages of abnormal clinical and placental variables, respectively; group 3 featured the highest percentages of multiple pregnancy, the heaviest placentas, and the most common acute chorioamnionitis, fetal inflammatory response; and group 1 had the highest proportion of mild erythroblastosis of fetal blood. When comparing groups 1 and 3, 21 of 29 clinical risk factors/outcomes (72.4%) and 30 of 41 placental variables (73.2%) were more common in group 1.Results.—

Presence of diffuse hypoxic patterns of placental injury adds prognostically negative significance to increased vascularity of chorionic villi. Chorangiosis without those patterns portends minimal risk for the pregnancy, and is associated with significantly fewer pregnancy risk factors, abnormal outcomes, and other placental abnormalities.Conclusions.—

A prospective study of villous capillary lesions in complicated pregnancies

The vascularity of placental tissue is dependent on various factors of which fetomaternal hypoxia plays a major role. Hypoxia can be of different types and each type influences the vascularity of the villi, especially terminal villi, in its own way. In this study, we attempted to identify villous vascular changes in a group of term placentae from mothers with diseases complicating pregnancy. Chorangiosis was the most frequently identified lesion while chorangioma was found in only 2 cases. There were no cases of chorangiomatosis. A few cases had normal villous vasculature. Maternal diseases have a major role in disrupting the placental vasculogenesis and angiogenesis by creating a hypoxic environment that may affect the fetus adversely. Hence, such conditions need to be identified early in pregnancy and managed appropriately as it is possible to maintain a normal vasculature and prevent neonatal mortality and morbidity if prompt intervention is done.

Angiogenesis in villous chorangiosis observed by ultrastructural studies

Chorangiosis is microscopically designated as more than ten terminal capillaries within the villous stroma of the placenta and is mostly related to chronic fetal hypoxia. However, the histogenetic relationship between increased number of terminal villous capillaries and chronic hypoxia has not yet been clarified. Of 665 placentas histologically examined at Saitama Medical University from 2003 to 2010, chorangiosis was found in 58 cases (8.7 %), which were mostly more than 35 gestational weeks. In addition, low birth weight (less than 2,500 g) infants (74.1 %) and those who suffered from cardiac anomalies, chromosome anomalies, and single umbilical artery comprised 32.7 % of cases. Placental lesions were associated with chorangiosis involved in infarct (46.6 %), intervillous thrombosis (20.7 %), and marginal hemorrhages (22.4 %). Scanning electron microscopic studies showed narrowing of vessel ostium and disorders of endothelium in the umbilical cord vessel complicated by chorangiosis. Furthermore, in transmission electron microscopic observation, not only the chorionic villi had multiple enlarged vessels within the villous stroma, but we also found that new capillaries were formed by angiogenesis with endothelial cells derived from fibroblasts under the chronic hypoxic state.

Severe transient cardiac failure caused by placental chorangiosis

BACKGROUND

Chorangiomas are villous capillary tumors of the placenta with high impact on neonatal morbidity and mortality. Cardiac complications have occasionally been reported.

OBJECTIVE

To elucidate clinical features, diagnosis and treatment of cardiac failure caused by chorangiomas.

METHOD

We report a case of a newborn, in whom massive chorangiomas were associated with severe cardiac failure, anemia, and thrombocytopenia.

RESULTS

Chorangiosis was not diagnosed prenatally. The pre-existing cardiac failure of the infant deteriorated soon after birth. Despite the severe stage, cardiac failure was reversible with intensive medical treatment including phosphodiesterase inhibitor. Complete recovery with no signs of cardiomyopathy was confirmed at the age of 5 months.

CONCLUSIONS

Severe cardiac failure in the neonate can be caused by chorangiosis. The time of diagnosis and treatment seems to be critical for the outcome of the infant. Prenatal treatment interventions should be considered.

Clinico-pathological profile of 12 cases of chorangiosis

Chorangiosis is one of the vascular lesions that involves terminal chorionic villi. It is commonly associated with various feto-maternal conditions like pre-eclampsia, diabetes etc. However, the clinical significance of this pathological finding has not been studied extensively. The aim of this study was to identify the various conditions associated with chorangiosis and to determine its clinical significance. A retrospective study to identify the cases of placentas diagnosed with chorangiosis was carried out and the clinical and morphological details of these cases were reviewed. Immunostaining for CD34 and muscle-specific actin was also performed to confirm chorangiosis and to exclude chorangiomatosis. A total of 12 cases of chorangiosis were retrieved, most of them were of term gestation. Five of these 12 cases were associated with various maternal conditions including syphilis (2 cases) and single cases of pre-eclampsia, diabetes and jaundice. One case in each had abruptio placenta and non-immune hydrops. Of these 12 cases, seven were stillborn. Microscopically, all 12 cases showed extensive chorangiosis involving terminal villi. In addition, two cases showed focal infarction and one had extensive calcification. Immunostaining for CD34 confirmed increased number of capillaries while muscle-specific actin was negative, excluding chorangiomatosis. The clinico-pathological profile presented in this study suggests that chorangiosis has characteristic pathological features for its recognition and needs to be differentiated from similar conditions like chorangioma and chorangiomatosis. Also, chorangiosis has potential clinical significance and should be mentioned in the pathology report and the patient should be investigated for associated conditions like syphilis, pre-eclampsia, diabetes etc.