Chorangioma and related vascular lesions of the placenta--a review

Large Chorioangioma in Triplets: An Uncommon Occurrence

A 25-year-old primigravida presented at 26 weeks of gestation by dates, the first time for the routine antenatal checkup. No histories were suggestive of pregnancy-induced hypertension (PIH) and edema. On physical examination, pallor was present with microcytic hypochromic anemia. Raised beta-human chorionic gonadotropin (HCG) and alpha-fetoprotein (AFP) levels were present. Ultrasonography revealed triples with two thin echogenic intertwining membranes. Anomaly scan did not reveal any abnormality in fetuses. The placenta showed a large oval hypoechoic mass arising from its edge and bulge into the amniotic fluid. A central feeding vessel with a branching pattern and pulsatile color flow like that of the umbilical artery is noted on the color Doppler. She was spontaneously preterm delivered vaginally at 28 weeks of gestation. All three fetuses were stillborn. Histopathological diagnosis of angiomatous chorioangioma was confirmed. This case classically represents a grave complication of the large chorioangioma.

Machine learning classification of placental villous infarction, perivillous fibrin deposition, and intervillous thrombus

INTRODUCTION

Placental parenchymal lesions are commonly encountered and carry significant clinical associations. However, they are frequently missed or misclassified by general practice pathologists. Interpretation of pathology slides has emerged as one of the most successful applications of machine learning (ML) in medicine with applications ranging from cancer detection and prognostication to transplant medicine. The goal of this study was to use a whole-slide learning model to identify and classify placental parenchymal lesions including villous infarctions, intervillous thrombi (IVT), and perivillous fibrin deposition (PVFD).

METHODS

We generated whole slide images from placental discs examined at our institution with infarct, IVT, PVFD, or no macroscopic lesion. Slides were analyzed as a set of overlapping patches. We extracted feature vectors from each patch using a pretrained convolutional neural network (EfficientNetV2L). We trained a model to assign attention to each vector and used the attentions as weights to produce a pooled feature vector. The pooled vector was classified as normal or 1 of 3 lesions using a fully connected network. Patch attention was plotted to highlight informative areas of the slide.

RESULTS

Overall balanced accuracy in a test set of held-out slides was 0.86 with receiver-operator characteristic areas under the curve of 0.917-0.993. Cases of PVFD were frequently miscalled as normal or infarcts, the latter possibly due to the perivillous fibrin found at the periphery of infarctions. We used attention maps to further understand some errors, including one most likely due to poor tissue fixation and processing.

DISCUSSION

We used a whole-slide learning paradigm to train models to recognize three of the most common placental parenchymal lesions. We used attention maps to gain insight into model function, which differed from intuitive explanations.

Chorioangioma: a single tertiary care center retrospective study

OBJECTIVES

Chorioangioma represents a challenge due to the rarity of the condition, paucity of sufficient management guidelines, and controversies regarding the best invasive fetal therapy option; most of the scientific evidence for clinical treatment has been limited to case reports. The aim of this retrospective study was to review the natural antenatal history, maternal and fetal complications, and therapeutic modalities used in pregnancies complicated with placental chorioangioma at a single Center.

METHODS

This retrospective study was conducted at King Faisal Specialist Hospital and Research Center (KFSH&RC) in Riyadh, Saudi Arabia. Our study population included all pregnancies with ultrasound features of chorioangioma, or histologically confirmed chorioangiomas, between January 2010 and December 2019. Data were collected from the patients' medical records, including the ultrasound reports and histopathology results. All subjects were kept anonymous; case numbers were used as identifiers. Data collected by the investigators were entered into Excel worksheets in an encrypted format. A MEDLINE database was used to retrieve 32 articles for literature review.

RESULTS

Over a 10-year period between January 2010 and December 2019, 11 cases of chorioangioma were identified. Ultrasound remains the gold standard for diagnosis and follow-up of the pregnancy. Seven of the 11 cases were detected by ultrasound, allowing proper fetal surveillance and antenatal follow-up. Of the remaining six patients, one underwent radiofrequency ablation, two underwent intrauterine transfusion for fetal anemia due to placenta chorioangioma, one had vascular embolization with an adhesive material, and two were managed conservatively until term with ultrasound surveillance.

CONCLUSIONS

Ultrasound remains the gold standard modality for prenatal diagnosis and follow-up of pregnancies with suspected chorioangiomas. Tumor size and vascularity play a significant role in the development of maternal-fetal complications and the success of fetal interventions. To determine the superior modality of fetal intervention mandates more data and research; nevertheless, Fetoscopic Laser Photocoagulation and embolization with adhesive material seem to be a lead choice, with reasonable fetal survival.

Mixed chorangioma and leiomyoma of the placenta, with a brief review of nontrophoblastic placental lesions

Chorangioma is the most common type of primary non-trophoblastic tumor of the placenta, usually identified incidentally on ultrasound or at delivery. Leiomyomas within the placenta have been described, though they are rare and usually of maternal origin. We present an unusual case of a placental tumor with combined histopathologic and immunohistochemical features of both chorangioma and leiomyoma. A 39-year-old woman was found to have an echogenic placental mass at 33 weeks of gestation on ultrasound, that was thought to be a chorangioma. They followed up weekly, and performed a cesarean section at 39 weeks, due to concern for intrauterine growth restriction. No fetal or maternal complications occurred. Grossly, a 9-cm, red-brown mass with a broad-based stalk was identified on the fetal surface of the placenta near the periphery. Microscopically, the lesion was found to display characteristic features of chorangioma, with vascular proliferation, which stained positive for CD34 and CD31. SMA and caldesmon immunohistochemical staining was also positive, highlighting the proliferation of smooth muscle throughout the neoplasm. Literature review revealed a single additional case with similar characteristics.

Large Hemoglobin Differences at Birth in Monochorionic Twins with a Placental Chorangioma and Delayed Cord Clamping

We report a case of a monochorionic diamniotic twin with an uncomplicated pregnancy, but with an unexpected large intertwin hemoglobin (Hb) difference at birth. Twin 1 was delivered vaginally and had an uneventful neonatal course. The umbilical cord of Twin 1 was clamped approximately 5 min after birth. After the birth of Twin 1, Twin 2 developed severe bradycardia and showed limited cardiac output on ultrasound, for which an emergency cesarean section was performed. A full blood count revealed an Hb of 20.1 g/dL for Twin 1 and 10.2 g/dL for Twin 2 (intertwin difference 9.9 g/dL). Reticulocyte counts were similar, 40‰ and 38‰, respectively. Placental examination revealed 10 vascular anastomoses, including one arterio-arterial anastomosis with a diameter of 1.4 mm. Additionally, a large chorangioma was present on the placental surface of Twin 2. There was no color difference on the maternal side of the placenta. Based on the reticulocyte count ratio and the placental characteristics, twin anemia polycythemia sequence was ruled out as the cause of the large intertwin Hb difference. In this report, we discuss the various potential causes that could explain the large intertwin Hb difference including the role of delayed cord clamping in Twin 1, and the role of a large chorangioma, which may have attracted blood from the fetal circulation of Twin 2.

Central 22q11.2 deletion (LCR22 B-D) in a fetus with severe fetal growth restriction and a mother with severe systemic lupus erythematosus: Further evidence of CRKL haploinsufficiency in the pathogenesis of 22q11.2 deletion syndrome

22q11.2 deletion syndrome (22q11.2 DS, MIM #188400) is the most common chromosomal microdeletion with an incidence of 1 in 4000 live births. 22q11.2 DS patients present with varying penetrance and a broad phenotypic spectrum including dysmorphic features, congenital heart defects, hypoplastic thymus and T-cell deficiency, and hypocalcemia. The typical deletion spans 3 Mb between 4 large blocks of repetitive DNA, known as low copy repeats (LCRs), on chromosome 22 (LCR22) A and D. This deletion is found in ~85% of 22q11.2 DS patients, while only 4-5% have central LCR22B-D (1.5 Mb) and LCR22C-D (0.7 Mb) deletions. We report on a prenatally diagnosed, inherited case of central LCR22B-D 22q11.2 DS, born to a 22-year-old female with multiple autoimmune disorders. These include Sjogren's-syndrome-related antigen A (SSA+) severe systemic lupus erythematosus (SLE) with cutaneous and discoid components and seronegative antiphospholipid syndrome. Amniocentesis was performed due to fetal growth restriction (FGR). FISH with TUPLE1 (HIRA) probe was normal; however, chromosomal microarray identified a ~737 kb heterozygous loss between LCR22B-D. Subsequently, the same deletion was identified in the mother, which included CRKL and 19 other genes but excluded HIRA and TBX1, the typical candidate genes for 22q11.2DS pathogenesis. This case explores how loss of CRKL may contribute to immune dysregulation, as seen in the multiple severe autoimmune phenotypes of the mother, and FGR. Our experience confirms the importance of thorough workup in individuals with reduced penetrance of 22q11.2 DS features or atypical clinical presentations.

Circulating angiogenic profiles and histo-morphological placental characteristics of uncomplicated post-date pregnancies

INTRODUCTION

The objectives of this study were to describe the histo-morphology of post-date placentas in clinically uncomplicated pregnancies without adverse delivery outcomes and the association with maternal circulating pre-delivery Placental Growth Factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFlt-1), as well as the sFlt-1/PlGF ratio.

METHODS

Post-date placentas (gestational week ≥40⁺², n = 87) were macroscopically and histo-morphologically assessed according to the international, standardized Amsterdam Workshop Consensus Group criteria. Inter-rater agreement was evaluated by percentage of agreement. PlGF and sFlt-1 concentrations were available from maternal serum sampled close to delivery, and were compared by Mann-Whitney U test. Linear regression analyses were adjusted for predefined potential confounders.

RESULTS

The majority of the post-date placentas showed morphological signs of delayed maturation. About half of the placentas showed increased syncytial knotting and fibrin. In placentas with increased presence of intervillous fibrin, median maternal PlGF level was significantly lower (p = 0.004), median sFlt-1 level higher and sFlt-1/PlGF ratio significantly higher (p = 0.002) compared to those with normal fibrin amounts. Increased placental syncytial knotting was associated with lower levels of PlGF, higher sFlt-1 and higher sFlt-1/PlGF ratio compared to those with normal knotting.

DISCUSSION

Our standardized morphological study of post-date placentas in clinically healthy women with uncomplicated pregnancies and delivery outcomes revealed delayed maturation in the majority of placentas. Increased pre-delivery circulating anti-angiogenic profile was associated with increased intervillous fibrin and syncytial knotting. We propose that circulating maternal angiogenic biomarkers may be of future use in clinical post-date pregnancy assessment, as they reflect important aspects of placental health and function.

CD133 Expression in Placenta Chorioangioma Presenting as a Giant Asymptomatic Mass

Background: Placental chorioangioma is the most common benign non-trophoblastic neoplasm of the placenta. Its clinical relevance lies in the size of the tumor since larger masses cause pregnancy complications, including an unfavorable neonatal outcome. Case presentation: We report the case of a 34-year-old second gravida and nullipara at the 35th week of gestation, admitted to the gynecological department for antibiotic-resistant fever. The cardiotocography performed during hospitalization showed an abnormal fetal pattern. A 2250 g newborn was delivered by cesarean section. No complications were observed during childbirth and postpartum was insignificant. On gross inspection a white fleshy intraparenchymal mass blooming on the maternal surface was noted; routinely stained sections revealed features consistent with chorioangioma with vascular channels lined by inconspicuous endothelial cells immunoreactive for CD31 and CD133. Focal expression of CD133 was also observed in placental villi. Discussion: CD133 expression indicated the presence of stem cells in chorioangioma, suggesting their possible role in the development of mesenchymal lesions including chorioangioma.

Inflammatory myofibroblastic tumors associated with the placenta: a series of 9 cases

Inflammatory myofibroblastic tumors (IMTs) of the uterus are often associated with pregnancy and are delivered with the placenta. We describe the clinical, pathologic, and molecular findings in nine cases of placenta-associated IMT (PaIMT). All the lesions were incidentally discovered at delivery or on placental pathological examination. The maternal age ranged from 21 to 41 (mean = 30.6) years. Eight patients had high-risk pregnancies, and when known, all patients were multigravida. Macroscopically, eight tumors were well defined, ranging in size from 2 to 6 cm present at the maternal surface of the placenta (n = 3) and membranes (n = 4) or separately delivered with the placenta (n = 2). All nine lesions revealed classical IMT morphology with spindle cells associated with a lymphoplasmacytic infiltrate and thin elongated vessels. Five showed decidualization, and five showed coagulative necrosis. All tumors expressed CD10. Of the seven tumors that were anaplastic lymphoma kinase (ALK) positive, six were confirmed to have an ALK rearrangement by fluorescence in situ hybridization (FISH), whereas one failed FISH testing. Fusions included TIMP3-ALK (n = 3), THBS1-ALK (n = 2), and a novel SYN3-ALK fusion (n = 1). Clinical follow-up was available in three patients, with no recurrence reported. There appears to be an increased frequency of uterine IMTs in pregnancy and associated with the placenta. No PaIMT has behaved aggressively, although follow-up has been quite limited. This may speak to a specific behavior of these tumors when associated with pregnancy.

Impact of intramural non-cavity-distorting leiomyoma on placental histopathology and perinatal outcome in singleton live births resulting from in vitro fertilization treatment

PURPOSE

To evaluate the effect of non-cavity-distorting intramural leiomyomas on the placental histopathology pattern and perinatal outcome in singleton live births resulting from in vitro fertilization treatment.

METHODS

The study population included all singleton live births following in vitro fertilization treatment with autologous oocytes during the period from 2009 to 2017. Primary outcomes included anatomical, inflammation, vascular malperfusion, and villous maturation placental features. Secondary outcomes included fetal, maternal, delivery, and perinatal complications.

RESULTS

A total of 1119 live births were included in the final analysis and were allocated to the group of pregnancies with non-cavity-distorting intramural myomas (n = 101) and without myomas (n = 1018). After the adjustment for confounding factors, the non-cavity-distorting intramural myomas were found to be significantly associated with assisted placental delivery (OR 2.4; 95% CI 1.5-3.9), furcate cord insertion (OR 3.6; 95% CI 1.4-9.3), circumvallate membranes insertion (OR 5.2; 95% CI 1.4-19.3), chronic deciduitis (OR 8.2; 95% CI 1.6-42.2), focal intramural fibrin deposition (OR 25.1; 95% CI 2.1-306.2), subchorionic thrombi (OR 3.6; 95% CI 1.7-7.6), maternal vasculopathy (OR 2.5; 95% CI 1.2-5.5), and chorangioma (OR 5.9; 95% CI 1.4-25.2) as well as with the failure of labor progress (OR 2.4; 95% CI 1.3-4.4) and induction (OR 3.2; 95% CI 1.2-9.0).

CONCLUSION

Intramural non-cavity-distorting myomas have a significant impact on the placental histopathology with a higher incidence of dysfunctional labor.

Multiple Chorangioma Following Long-Term Secondary Infertility: A Rare Case Report and Review of Pathologic Differential Diagnosis

Chorangioma (placental hemangioma) is a benign non-trophoblastic neoplasm of the placenta. Small chorangiomas are usually asymptomatic, but the giant and multiple ones rarely have a favorable outcome. We report a case of 29 weeks of gestational age (after long-term secondary infertility) with premature labor pain and undiagnosed multiple chorangioma leading to hydrops fetalis and neonatal death. Here we report the clinicopathological features of our case and chorangioma in general, along with comparison of different vascular lesions of placenta in terms of incidence, risk factors, complications, histologic origin, macroscopic and light and electron microscopic features.

Large placental chorioangioma: a potential effective in-utero treatment modality for radio frequency ablation

Background

Placenta chorioangiomas are common benign placental tumours. While microscopic chorioangiomas are frequent, macroscopic chorioangiomas of more than 5 cm are rare and often associated with fetal complications such as high output cardiac failure, fetal anaemia and stillbirth. Close monitoring and in-utero treatment are sometimes necessary to prevent adverse pregnancy outcome.

Case presentation

We present two cases of large placenta chorioangiomas with one case requiring surgical therapy with radiofrequency ablation (RFA) of tumour vessels, which resulted in a successful outcome of a live birth at term.

Conclusion

We conclude that RFA is an effective alternative treatment modality to fetoscopic laser therapy in utero for cases at risk of fetal cardiac failure and intrauterine demise in the presence of large chorioangiomas.

Genetic Analysis of Copy Number Variation in Large Chorangiomas

INTRODUCTION

Chorangioma (CA) is the most common nontrophoblastic, vascular tumor-like lesion of the placenta with a reported incidence of 0.5% to 1% in all examined placentas. The underlying molecular mechanisms of CAs are still poorly elucidated, and a systematic investigation of the genetic background of CAs has not previously been done.

MATERIALS AND METHODS

Tissue biopsies from 8 large (>40 mm) histologically confirmed CAs and 8 unaffected matched placenta controls, along with standard control DNA samples were analyzed for large genomic deletions and duplications using array comparative genomic hybridization (array-CGH) method.

RESULTS

Array-CGH analysis revealed no rare or novel copy number variants in the CA samples compared with either standard control DNA or unaffected placenta DNA from the same individual.

DISCUSSION

In this study, a systematic genetic investigation of 8 large CAs failed to demonstrate any large-scale pathogenic genetic changes. This lack of association might support a nongenetic, nontumorous origin of these lesions; however, additional genetic studies focusing on smaller genomic alterations are required to fully assess any possible genetic contribution.

Fetal interventional procedures and surgeries: a practical approach

The identification of congenital birth defects and fetal malformations continues to increase during the antenatal period with improved imaging techniques. Understanding of how to treat specific fetal conditions continues to improve outcomes from these treatment modalities. In an effort to further improvement in this field, we provide a review that begins with a brief background of fetal surgery including the history of fetal surgery, ethics surrounding fetal surgery, and considerations of how to treat the fetus during intervention. A synopsis of the most commonly encountered disease processes treated by fetal intervention/surgery including definitions, treatment modalities, and outcomes following fetal intervention/surgery is then provided. Within the sections describing each disease process, methodology is described that has helped with efficiency and success of procedures performed at our institution.

Diffuse Chorangiomatosis as a Cause of Cardiomegaly, Microangiopathic Hemolytic Anemia and Thrombocytopenia in a Newborn

INTRODUCTION

The hallmark of diffuse chorangiomatosis is capillary dysvasculogenesis, diffusely involving the placenta. It can cause massive placental enlargement and may have adverse fetal effects.

CASE REPORT

A 32 weeks gestation male infant was born via cesarean section and had a placenta weighing 900 g. There was diffuse vascular proliferation involving the stem villi and intermediate villi. Short Nucleotide Polymorphism (SNP) microarray analysis of the placenta showed no biparental mosaicism or loss of heterozygosity, ruling out placental mesenchymal dysplasia. The infant also had cardiomegaly, microangiopathic hemolytic anemia and thrombocytopenia which spontaneously improved over time.

CONCLUSION

Diffuse chorangiomatosis can be associated with hemolysis, thrombocytopenia and cardiomegaly in the newborn. However, once delivered, these findings can spontaneously resolve over time.

Sonographic Evaluation of a Large Placental Chorangioma

Placental chorangioma is a rare, benign tumor of the placenta. Chorangiomas are typically small, are asymptomatic, and pose no threat to pregnancy. However, in extreme cases, large placental chorangiomas can cause maternal and fetal complications associated with poor outcomes and fetal demise. Prenatal sonography is an accurate method for diagnosing these benign tumors based on grayscale imaging and color Doppler assessment of intratumoral vascularity. Early diagnosis is critical in predicting the potential for subsequent maternal and fetal complications, planning sonographic surveillance, treating maternal symptoms, and delivery planning. This case study discusses the diagnosis and management of a large placental chorangioma in an otherwise uncomplicated pregnancy.

Clinical Outcome in Singleton and Multiple Pregnancies with Placental Chorangioma

INTRODUCTION

Chorangiomas (CAs) are the most common non-trophoblastic tumor-like-lesions of the placenta. Although the clinical significance of small CAs is unknown, the large lesions are often associated with maternal and fetal complications. The aim of our study was to assess the maternal clinical characteristics and neonatal outcome in singleton and multiple pregnancies with placental CA.

MATERIALS AND METHODS

Among 15742 selected placentas 170 CAs were diagnosed. Pregnancy and neonatal outcomes were analyzed in singleton (n = 121) and multiple (n = 49) pregnancy groups including 121 and 100 neonates, respectively.

RESULTS

The frequency of APGAR score <7 at 5 minutes (p = 0,012), abnormal pulsatility index (p = 0,034), and abnormal blood flow class (p = 0,011) were significantly higher in neonates from singleton compared to multiple pregnancies. Significantly smaller CAs in singleton pregnancies were related to small for gestational age neonates (p = 0,00040) and neonates admitted to the neonatal care unit (p = 0,028). In singleton pregnancies, significantly smaller CAs were associated to maternal preeclampsia (p = 0,039) and larger CAs to multiparity (p = 0,005) and smoking (p = 0,001) groups. The frequency of preeclampsia was high in both singleton and multiple pregnancy groups (41,32% vs 26,53%, respectively), however, the difference did not reach the level of statistical significance.

DISCUSSION

A high incidence of preeclampsia in cohort of placental CA might lead to a possible recognition of CAs as potential morphologic indicator of placental hypoxia.

CONCLUSION

A more favorable pregnancy outcome in multiple gestations compared to the singleton gestations with CAs might reflect an adaptive mechanism for increased demand of oxygen and associated placental tissue hypoxia in this group.

Chorioamniotic membrane separation caused by the seromucinous collection from a placental chorioangioma

Placental chorioangioma is a benign non-trophoblastic tumor of the placenta that can have various adverse effects on the mother and fetus depending on its size. Chorioamniotic membrane separation is rare condition of detachment between the amniotic membrane and chorionic membrane. Chorioamniotic membrane separation after the second trimester of pregnancy is usually occurs after invasive procedures or may occur spontaneously; it is mostly associated with fetal abnormalities. Here, we report a case of chorioamniotic membrane separation that might be occurred caused by the seromucinous secretion from a placental chorioangioma.

Giant Placental Chorangioma: A Rare Case Report

Chorangioma is a nontrophoblastic benign vascular tumour of the placenta, arising from the primitive chorionic mesenchyme. The clinical significance is related to the size of the tumours. Small chorangiomas, with a frequency of about 1%, are often asymptomatic. On the contrary, giant chorangiomas, greater than 5 cm in diameter, are rare tumours, with prevalence ranging from 1:9,000 to 1:50,000, and often associated with a variety of pregnancy complications and a poor perinatal outcome. We report a case of 26-year-old female who presented to us at 36 weeks of gestation with pain in the lower abdomen. Ultrasonograpy revealed polyhydramnios and a vascular tumour on the surface of placenta. Proper conservative antenatal management was done and a full term healthy baby was delievered. Histopathological examination of the extracted mass confirmed the diagnosis of chorangioma. The novelty of this report lies in the presence of large nontrophoblastic vascular placental tumour and the absence of any fetal complications. We emphasise the need of regular and timely antenatal management to diagnose and treat the complications of chorangioma at an early stage.

Prenatal Therapy of Large Placental Chorioangiomas: Case Report and Review of the Literature

Objective To review techniques and outcomes of different prenatal treatments for large placental chorioangiomas. Study Design Presentation of a case of laparoscopic-assisted laser coagulation and a systematic review of the literature for articles related to intervention for placental chorioangioma. Results A total of 37 cases of definitive (n = 23) and supportive therapy (n = 14) were evaluated, including one case treated in our center. Approximately 35% of the patients had a spontaneous preterm delivery in definitive treatment group versus 36% in the supportive group. The infant survival rates were 65 and 71% in the two groups, respectively. We further compared the two types of laser ablation (fetoscopic [n = 10] and interstitial [n = 4]). Approximately 30% of the patients in the fetoscopic and 25% in interstitial group, had a spontaneous preterm delivery. Survival rates were 60 and 100% in fetoscopic and interstitial groups, respectively. Conclusion Laser ablation and embolization of chorioangiomas via minimally invasive approach may prevent or reverse fetal hydrops due to high cardiac states. However, further studies are needed to refine the appropriate selection criteria that will justify the risk of this invasive in utero therapy for chorioangiomas.

Chorangioendothelioma of the Placenta: A Myth or Reality?

Chorangiomas of the placenta are often discovered incidentally and, although they are not common (1 in 9000 to 1 in 50 000 placentas), these tumors may be found in 0.5% to 1% of carefully examined placentas. The vast majority are of no clinical importance and complications are seen only in association with tumors measuring more than 4 cm in diameter. In contrast, hemangioendotheliomas are vascular tumors with varying grades of malignant potential and hardly ever involve the placenta. Here we describe a large placental chorangioma causing fetal hydrops and demonstrating distinctive intravascular luminal endothelial proliferation and tufting. To the best of our knowledge, this is probably only the second case of a placental hemangioendothelioma reported in the literature.

Extrafetal Findings on Fetal Magnetic Resonance Imaging: A Pictorial Essay

Although US is the mainstay of fetal imaging, magnetic resonance imaging (MRI) has become an invaluable adjunct in recent years. MRI offers superb soft tissue contrast that allows for detailed evaluation of fetal organs, particularly the brain, which enhances understanding of disease severity. MRI can yield results that are similar to or even better than those of US, particularly in cases of marked oligohydramnios, maternal obesity, or adverse fetal positioning. Incidentally detected extrafetal MRI findings are not uncommon and may affect clinical care. Physicians interpreting fetal MRI studies should be aware of findings occurring outside the fetus, including those structures important for the pregnancy. A systematic approach is necessary in the reading of such studies. This helps to ensure that important findings are not missed, appropriate clinical management is implemented, and unnecessary follow-up examinations are avoided. In this pictorial essay, the most common extrafetal abnormalities are described and illustrated.

Atypical Cellular Chorangioma: A Potential Diagnostic Pitfall With Worrisome Aspects but a Favorable Prognosis

Chorangiomas are rather frequent neoplasms encountered on placental examination but in rare cases they present some worrisome histological features that could alarm the pathologist and be misinterpreted as a malignant neoplasm, even if their biological behavior is favorable. We describe an unusual chorangioma with high cellularity and abundant mitosis that, after careful examination and postpartum follow-up, showed benign clinical course for mother and child confirming previous reported cases. This type of tumor is known in the literature as atypical cellular chorangioma and its identification is important in order to exclude potentially dangerous overtreatment.

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.

Chorangiomatosis: Evaluation of a placental vascular lesion and related clinical effects

BACKGROUND

Chorangiomatosis is a unique placental vascular abnormality that can cause growth retardation and even fetal demise in severe cases. In this study we aim to better understand this lesion and the possible clinical implications.

METHODS AND MATERIALS

In this study 170 placentas were evaluated, both grossly and microscopically. The patients' charts were reviewed and relevant clinical data were extracted. In the histological examination, presence of placental lesions including chorangiomatosis (focal, multifocal and diffuse) and chorangiosis was determined and possible correlation between placental findings and clinical outcomes investigated.

RESULTS

Among the 170 placentas examined, 42 cases of multifocal chorangiomatosis (25.6%), 7 cases with diffuse chorangiomatosis (4.26%), and 56 cases of focal chorangiomatosis (34.1%) were identified. We found that there is a significant correlation between multifocal/diffuse chorangiomatosis and adverse clinical outcomes including lower birth weight and NICU admission.

CONCLUSION

Chorangiomatosis can significantly affect the outcomes of pregnancy and more research is needed to better understand this lesion.

Co-occurrence of multifocal chorioangiomatosis and mesenchymal dysplasia in preeclampsia

Chorioangioma is the most common benign vascular placental tumor. It is often small and has no clinical significance. Large chorioangiomata are rarer and can lead to fetal or maternal complications. Chorioangiomatosis is even rarer and is defined as a focal or multifocal proliferation of placental capillaries permeating villous tissue. Placental mesenchymal dysplasia (PMD) is characterized by the overgrowth of placental mesenchymal tissue and can be associated with fetal or obstetrical complications. We report a case associated with preeclampsia and intrauterine growth restriction, in which both chorioangiomatosis and PMD were present.

Placental Mesenchymal Dysplasia

Placental mesenchymal dysplasia is a rare, incompletely understood placental stromal lesion, characterized by placentomegaly and striking ectasia and tortuosity of chorionic plate and stem villous vessels. Its prenatal ultrasonographic and gross pathologic features resemble those of a partial mole, but the fetus is typically normal and the placenta has a diploid, chromosomal complement. We discuss the pathologic features and current understanding of the etiopathogenesis of this condition, the supportive immunohistochemical and confirmatory molecular genetic studies important in its diagnosis, and its implications for pregnancy and infant outcomes.

Modeling oxygen transport in human placental terminal villi

Oxygen transport from maternal blood to fetal blood is a primary function of the placenta. Quantifying the effectiveness of this exchange remains key in identifying healthy placentas because of the great variability in capillary number, caliber and position within the villus-even in placentas deemed clinically "normal". By considering villous membrane to capillary membrane transport, stationary oxygen diffusion can be numerically solved in terminal villi represented by digital photomicrographs. We aim to provide a method to determine whether and if so to what extent diffusional screening may operate in placental villi. Segmented digital photomicrographs of terminal villi from the Pregnancy, Infection and Nutrition study in North Carolina 2002 are used as a geometric basis for solving the stationary diffusion equation. Constant maternal villous oxygen concentration and perfect fetal capillary membrane absorption are assumed. System efficiency is defined as the ratio of oxygen flux into a villus and the sum of the capillary areas contained within. Diffusion screening is quantified by comparing numerical and theoretical maximum oxygen fluxes. A strong link between various measures of villous oxygen transport efficiency and the number of capillaries within a villus is established. The strength of diffusional screening is also related to the number of capillaries within a villus. Our measures of diffusional efficiency are shown to decrease as a function of the number of capillaries per villus. This low efficiency, high capillary number relationship supports our hypothesis that diffusional screening is present in this system. Oxygen transport per capillary is reduced when multiple capillaries compete for diffusing oxygen. A complete picture of oxygen fluxes, capillary and villus areas is obtainable and presents an opportunity for future work.