Capillary malformation--arteriovenous malformation syndrome: review of the literature, proposed diagnostic criteria, and recommendations for management

How many is too many? A review of the significant numbers in pediatric skin lesions and their recommended evaluation

Pediatric dermatologists are frequently consulted to evaluate children for cutaneous signs of systemic disorders. Numerical thresholds of significance have been described in the dermatologic literature for various skin findings where the likelihood of an associated extracutaneous abnormality or known genetic syndrome increases significantly. Knowledge of these numerical thresholds facilitates diagnosis and management, which improves clinical outcomes and avoids severe complications. This review highlights the clinical presentation, complications, evaluation, and numerical significance, when applicable, for the following skin findings: infantile hemangiomas, capillary malformations, café-au-lait macules, hypopigmented macules, juvenile xanthogranulomas, pilomatricomas, and angiofibromas.

Interdisciplinary Management of Vascular Anomalies in the Head and Neck

Vascular anomalies in the head and neck area are usually rare diseases and pose a particular diagnostic and therapeutic challenge. They are divided into vascular tumours and vascular malformations. A distinction is made between benign tumours, such as infantile haemangioma, and rare malignant tumours, such as angiosarcoma. Vascular malformations are categorised as simple malformations, mixed malformations, large vessel anomalies and those associated with other anomalies. Treatment is interdisciplinary and various modalities are available. These include clinical observation, sclerotherapy, embolisation, ablative and coagulating procedures, surgical resection and systemic drug therapy. Treatment is challenging, as vascular anomalies in the head and neck region practically always affect function and aesthetics. A better understanding of the genetic and molecular biological basis of vascular anomalies has recently led to clinical research into targeted drug therapies. This article provides an up-to-date overview of the diagnosis, clinic and treatment of vascular anomalies in the head and neck region.

Hereditary hemorrhagic telangiectasia: from signaling insights to therapeutic advances

Hereditary hemorrhagic telangiectsia (HHT) is an inherited vascular disorder with highly variable expressivity, affecting up to 1 in 5,000 individuals. This disease is characterized by small arteriovenous malformations (AVMs) in mucocutaneous areas (telangiectases) and larger visceral AVMs in the lungs, liver, and brain. HHT is caused by loss-of-function mutations in the BMP9-10/ENG/ALK1/SMAD4 signaling pathway. This Review presents up-to-date insights on this mutated signaling pathway and its crosstalk with proangiogenic pathways, in particular the VEGF pathway, that has allowed the repurposing of new drugs for HHT treatment. However, despite the substantial benefits of these new treatments in terms of alleviating symptom severity, this not-so-uncommon bleeding disorder still currently lacks any FDA- or European Medicines Agency-approved (EMA-approved) therapies.

Prevalence and Predictors of Hereditary Hemorrhagic Telangiectasia and Capillary-Malformation Arteriovenous Malformation Syndrome Among Children with Neurovascular Malformations

OBJECTIVE

To investigate the prevalence and predictors of hereditary hemorrhagic telangiectasia (HHT) and capillary-malformation arteriovenous malformation (CM-AVM) syndrome among children with no prior personal or family history of these diseases who presented with an arteriovenous shunt lesion.

STUDY DESIGN

A retrospective chart review was completed on patients aged 0 through 21 years with arteriovenous shunt lesions evaluated at our Cerebrovascular Center. Diagnosis of definite or suspected HHT or CM-AVM was based on clinical features and genetic testing. Associations between final diagnosis and type and number of lesions, epistaxis, telangiectasias, CM, and pulmonary AVMs were assessed.

RESULTS

Eighty-nine patients were included. Thirteen (14.6%) had definite HHT, 11 (12.4%) suspected HHT, and 4 (4.5%) definite CM-AVM. Having ≥2 episodes of epistaxis/year and ≥ 2 sites with telangiectasias were each associated with definite HHT (P < .001). Having ≥ 2 CM was associated with definite CM-AVM (P < .001). Pulmonary AVM was associated with increased odds of having definite HHT (OR = 6.3, 95% CI: 1.2-33.4). Multiple lesions (OR = 24.5, 95% CI: 4.5-134.8) and arteriovenous fistulas (OR = 6.2, 95% CI: 1.9-20.3) each increased the likelihood of having definite HHT or CM-AVM. Genetic testing was positive in 31% of patients tested.

CONCLUSIONS

We recommend that children with neurovascular shunt lesions be offered genetic testing and undergo further evaluation for HHT and CM-AVM. Awareness and early diagnosis of these conditions is a critical step toward improving long-term outcomes and preventing disease-associated complications.

Molecular and genetic mechanisms in brain arteriovenous malformations: new insights and future perspectives

Brain arteriovenous malformations (bAVMs) are rare vascular lesions made of shunts between cerebral arteries and veins without the interposition of a capillary bed. The majority of bAVMs are asymptomatic, but some may be revealed by seizures and potentially life-threatening brain hemorrhage. The management of unruptured bAVMs remains a matter of debate. Significant progress in the understanding of their pathogenesis has been made during the last decade, particularly using genome sequencing and biomolecular analysis. Herein, we comprehensively review the recent molecular and genetic advances in the study of bAVMs that not only allow a better understanding of the genesis and growth of bAVMs, but also open new insights in medical treatment perspectives.

RASopathies due to de novo pathogenic variants: clinical features, genetic findings and outcomes in nine neonates born with congenital heart defects

Background

There are limited information available related to neonatal characteristics of RASopathies, a group of autosomal dominant syndromes with considerable phenotypic overlap.

Methods

The retrospective review revealed 9 neonates born with congenital heart defects (CHDs) and diagnosed as RASopathies due to de novo mutations (DNMs) by trio-based exome sequencing (ES) between January 2017 and December 2020. We report in details of the neonatal course, molecular analysis and 180-days of age follow-up in affected individuals.

Results

The early clinical spectrum included various types of CHDs, less noticeable multiple extracardiac anomalies and unspecific symptoms like poor feeding. Of the 8 variants identified from 6 genes, 2 in RASA1 were novel: (NM_002890.2: c.2828 T > C (p.Leu943Pro)) and (NM_002890.2: c.2001del (p.Pro668Leufs*10)), which functionally impaired the protein structure. There was a relatively high mortality rate of 33.33% (3/9) for all the defects combined. A RAF1-deficient male and a RASA1-deficient male survived from severe heart failure by surgical interventions in early life.

Conclusions

Our results revealed that family-based ES was useful in identifying DNMs and causal genes for sporadic diseases and screening Rasopathies shortly after birth. We recommended a family-based ES and a full phenotypic evaluation including echocardiogram, magnetic resonance imaging, ultrasonography and coagulation screening in neonates with CHDs and a suspected genetic etiology.

Lasers for cutaneous lesions: An update

There are several types of medical settings which use lasers. Dermatologists use lasers as it is non-invasive with preferential cosmetic outcomes and finer wound healing. The types of lasers are relying on their wavelengths and delivery systems. Over time, by using several distinct devices and strategies, new lasers have been generated; as a consequence, they are manipulated in a wide range of dermatological settings. In this review, laser applications in various vascular, infectious, and hyperpigmented cutaneous lesions were framed. We aimed to represent the fitness of phototherapy for each condition as well as the overall challenges that face laser. In addition, low-level laser therapy, and laser resurfacing were noted as the marketable line of lasers in the current time for cosmetic purposes.

Capillary Malformation-arteriovenous Malformation Type 2: A Case Report and Review

Capillary malformation-arteriovenous malformation syndrome is a rare genodermatosis with cutaneous capillary malformations and a risk of associated fast-flow malformations. We describe here a four-generation family with a novel heterozygous pathogenic variant in the EPHB4 gene (NM_004444.5 (EPHB4): c.2224G>C, p.(Ala742Pro)). A review of the literature retrieved 127 patients with capillary malformation-arteriovenous malformation syndrome and confirmed variants in EPHB4. Multiple capillary malformations were present in 114 (89.76%) patients, and 12 (9.44%) patients had a solitary capillary malformation. Arteriovenous malformations/fistulas were present in 23 (18.1%) patients, and were located within the central nervous system in 5 (3.9%) patients. Not all papers included description of epistaxis. Telangiectasias were reported in 28 (22%) patients, and Bier spots were described in 20 (15.7%) patients. The clinical characteristics of capillary malformation-arteriovenous malformation syndrome are diverse and often discrete, which can make it difficult to distinguish capillary malformationarteriovenous malformation syndrome from hereditary haemorrhagic telangiectasia.

RASopathies: Dermatologists’ viewpoints

Ras/mitogen-activated protein kinase pathway dysregulation results in a group of disorders, collectively termed as RASopathies. Neurofibromatosis type 1, Noonan syndrome, Noonan syndrome with multiple lentigines, Noonan syndrome/loose anagen hair, Legius syndrome, Costello syndrome, cardio-facio-cutaneous syndrome and capillary malformation-arteriovenous malformation are the well-recognized RASopathies. These are characterized by multi-organ tumours and hamartomas. Some other features in common are facial dysmorphism, skeletal abnormalities, congenital heart disease, neurocognitive abnormalities and risk of various solid-organ and haematological malignancies. Some of the RASopathies are heterogeneous, caused by several gene mutations resulting in variations in phenotypes and severity ranging from mild to fatal. Significant phenotypic overlaps among different disorders, often makes it difficult to pinpoint a clinical diagnosis. Specific cutaneous manifestations are present in some of the RASopathies and are often the earliest clinical signs/symptoms. Hence, dermatologists contribute significantly as primary care physicians by identifying disorder-specific cutaneous lesions. However, diagnostic work-up and management of these disorders are often multidisciplinary. Confirmation of diagnosis is possible only by genetic mapping in each case. Genetic counseling of the patients and the affected families is an important component of the management. The aim of this review is description of cutaneous manifestations of RASopathies in the background of multi-system involvement to enable dermatologists a comprehensive and logical approach to work up and diagnose such patients in the absence of facility for specific molecular testing.

Imaging Manifestations and Interventional Treatments for Hereditary Hemorrhagic Telangiectasia

Hemorrhagic hereditary telangiectasia (HHT) is a rare autosomal dominant disorder that causes multisystem vascular malformations including mucocutaneous telangiectasias and arteriovenous malformations (AVMs). Clinical and genetic screening of patients with signs, symptoms, or a family history suggestive of HHT is recommended to confirm the diagnosis on the basis of the Curaçao criteria and prevent associated complications. Patients with HHT frequently have epistaxis and gastrointestinal bleeding from telangiectasias. Pulmonary AVMs are common right-to-left shunts between pulmonary arteries and veins that can result in dyspnea and exercise intolerance, heart failure, migraine headaches, stroke or transient ischemic attacks, brain abscesses, or in rare cases, pulmonary hemorrhage. Primary neurologic complications from cerebral AVMs, which can take on many forms, are less common but particularly severe complications of HHT. Multimodality imaging, including transthoracic echocardiography, Doppler US, CT, and MRI, is used in the screening and initial characterization of vascular lesions in patients with HHT. Diagnostic angiography is an important tool in characterization of and interventional treatments for HHT, particularly those in the lungs and central nervous system. A multidisciplinary approach to early diagnosis, treatment, imaging, and surveillance at high-volume HHT Centers of Excellence is recommended. Although a variety of idiopathic, traumatic, or genetic conditions can result in similar clinical and imaging features, the Curaçao criteria are particularly useful for the proper diagnosis of HHT. Imaging and treatment options are reviewed, with a focus on screening, diagnosis, and posttreatment findings, with the use of updated international guidelines. Online supplemental material is available for this article. ^©RSNA, 2021.

RASopathies: The musculoskeletal consequences and their etiology and pathogenesis

The RASopathies comprise an ever-growing number of clinical syndromes resulting from germline mutations in components of the RAS/MAPK signaling pathway. While multiple organs and tissues may be affected by these mutations, this review will focus on how these mutations specifically impact the musculoskeletal system. Herein, we review the genetics and musculoskeletal phenotypes of these syndromes in humans. We discuss how mutations in the RASopathy syndromes have been studied in translational mouse models. Finally, we discuss how signaling molecules within the RAS/MAPK pathway are involved in normal and abnormal bone biology in the context of osteoblasts, osteoclasts and chondrocytes.

CM-AVM syndrome - A prospective observational study of unrelated paediatric cases

OBJECTIVE

The main objective of this study is to describe the clinical spectrum of CM-AVM syndrome as well as radiological and genetic findings.

METHODS

This is a single-centre prospective observational study performed at Sydney Children's Hospital. Patients under the age of 18 years that presented to our paediatric dermatology clinic or vascular birthmark clinic between January 2015 and September 2020 with one or more geometric shaped pink/ red/ brown macule with a peripheral pallor characteristic of a high-flow vascular stain were included. Children subsequently diagnosed with other diagnosis or family members with CM-AVM syndrome were excluded.

RESULTS

Sixty children were included, with two subsequently excluded. A third of patients (n = 22, 38%) presented with a single characteristic HFVS, whereas the remaining two thirds (n = 36; 62%) had multiple HFVS. In children with multiple HFVS, one notably larger HFVS was detected in the majority of children (n = 32, 88%). In 33 patients, a brain and spine MRI was performed, which detected a spine AVM in one symptomatic patient with sensorimotor deficits. No cerebral AVM or AVF was picked up in the cohort. A RASA 1 result was available for evaluation in 24, of which 16 (67%) were positive. An EPHB4 result was available in eight, two (25%) of which were positive.

CONCLUSIONS

One large HFVS often accompanied by multiple small HFVS can be seen in most patients. Despite of the lack of genetic confirmation of diagnosis in single lesions, this phenotype might be of interest and warrants further investigation.

Vascular endothelial cell specification in health and disease

There are two vascular networks in mammals that coordinately function as the main supply and drainage systems of the body. The blood vasculature carries oxygen, nutrients, circulating cells, and soluble factors to and from every tissue. The lymphatic vasculature maintains interstitial fluid homeostasis, transports hematopoietic cells for immune surveillance, and absorbs fat from the gastrointestinal tract. These vascular systems consist of highly organized networks of specialized vessels including arteries, veins, capillaries, and lymphatic vessels that exhibit different structures and cellular composition enabling distinct functions. All vessels are composed of an inner layer of endothelial cells that are in direct contact with the circulating fluid; therefore, they are the first responders to circulating factors. However, endothelial cells are not homogenous; rather, they are a heterogenous population of specialized cells perfectly designed for the physiological demands of the vessel they constitute. This review provides an overview of the current knowledge of the specification of arterial, venous, capillary, and lymphatic endothelial cell identities during vascular development. We also discuss how the dysregulation of these processes can lead to vascular malformations, and therapeutic approaches that have been developed for their treatment.

Clinical and molecular characterization of patients with hereditary hemorrhagic telangiectasia: Experience from an HHT Center of Excellence

In this retrospective single-center study, we evaluated whether/how pathogenic/likely pathogenic variants of three hereditary hemorrhagic telangiectasia (HHT)-associated genes (ENG, ACVRL1, and SMAD4) are associated with specific clinical presentations of HHT. We also characterized the morphological features of pulmonary arteriovenous malformations (AVMs) in patients with these variants. Pathogenic or likely pathogenic variants were detected in 64 patients. Using nonparametric statistical tests, we compared the type and prevalence of specific HHT diagnostic features associated with these three variants. Pathogenic variants in these genes resulted in gene-specific HHT clinical presentations. Epistaxis was present in 93%, 94%, and 100% of patients with ENG, ACVRL1, and SMAD4 variants, respectively (p = 0.79). Pulmonary AVMs were more common in patients with the ENG variant (p = 0.034) compared with other subgroups. ACVRL1 variant was associated with the lowest frequency of pulmonary AVMs (p = 0.034) but the highest frequency of hepatic AVMs (p = 0.015). Patients with the ACVRL1 variant did not have significantly more pancreatic AVMs compared with the other groups (p = 0.72). ENG, ACVRL1, and SMAD4 pathogenic or likely pathogenic variants are associated with gene-specific HHT presentations, which is consistent with results from other HHT centers.

Capillary malformation-arteriovenous malformation syndrome: a multicentre study

BACKGROUND

Capillary malformation-arteriovenous malformation (CM-AVM) syndrome is a rare syndrome with characteristic skin lesions that are associated with fast-flow vascular malformations (FFVMs) in one-third of patients. Few case series have been described, and none in Spain.

AIM

To identify the prevalence of dermatological parameters, FFVMs and associated features in a large series of patients with CM-AVM.

METHODS

We conducted an observational study of patients with CM-AVM syndrome diagnosed in 15 Spanish hospitals over 3 years. The main clinical, radiological, genetic findings and associated diseases were analysed.

RESULTS

In total, 64 patients were assessed. In 26.5% of cases, the diagnosis was incidental. In 75% of patients, there was one significantly larger macule, which we termed the 'herald patch'. FFVMs were detected in 34% of the patients, with 30% located on the skin, 7.8% in the brain and in 1.5% in the spine. There was a positive family history in 65% of the 64 patients. Genetic analysis was performed for RASA1 mutations in 57 patients, of whom 42 (73%) had a positive result. All 4 patients tested for EPHB4 mutations had a positive result. No tumour lesions were detected in the series, except for five infantile haemangiomas.

CONCLUSIONS

Our data on clinical lesions, associated FFVM, family history and genetics are similar to those previously published in the literature. An extensive data analysis failed to demonstrate any statistically significant association between the presence of an FFVM and any clinical, familial or genetic parameter that could predict its onset, although a link between the presence of a herald patch on the midline face and the presence of a brain FFVM was observed. We did not detect any genotype-phenotype correlation.

Unilateral and segmental distribution of facial erythema: is it a real port-wine stain?

Capillary malformation-arteriovenous malformations (CM-AVMs) caused by a RASA-1 or EPHB4 mutation are characterized as hereditary sporadic or multifocal capillary malformations (CMs), associated with potential fast-flow vascular anomalies underlying erythema lesions. Because of the similar phenotype, CM-AVMs should be considered in the differential diagnosis of isolated CMs as well as other disorders with an erythema phenotype, such as hereditary hemorrhagic telangiectasia (HHT).Herein, we report a male patient with facial erythema. Red lesions were located in the V1 region of his left face, the V2 and V3 regions on his right side, and the nasal back. The patient was initially thought to have PWSs because of the unilateral and segmental distribution of his red facial lesions. In contrast to a previous diagnosis, we diagnosed the child with capillary malformation-arteriovenous malformation type 2 (CM-AVM2) based on a family history of erythema, the results of physical examination and ultrasound raising potential fast-flow lesions, and a genetic study revealing a germline EPHB4 mutation. This study emphasizes the importance of differential diagnosis for PWS and CM-AVM. A single clinical diagnosis can be limited, and molecular diagnosis is recommended to provide more information for the evaluation of the potential risk of fast-flow lesions underlying erythema lesions if necessary.

Emerging importance of molecular pathogenesis of vascular malformations in clinical practice and classifications

Vascular malformations occur during early vascular development resulting in abnormally formed vessels that can manifest as arterial, venous, capillary or lymphatic lesions, or in combination, and include local tissue overdevelopment. Vascular malformations are largely caused by sporadic somatic gene mutations. This article aims to review and discuss current molecular signaling pathways and therapeutic targets for vascular malformations and to classify vascular malformations according to the molecular pathways involved. A literature review was performed using Embase and Medline. Different MeSH terms were combined for the search strategy, with the aim of encompassing all studies describing the classification, pathogenesis, and treatment of vascular malformations. Major pathways involved in the pathogenesis of vascular malformations are vascular endothelial growth factor (VEGF), Ras/Raf/MEK/ERK, angiopoietin-TIE2, transforming growth factor beta (TGF-β), and PI3K/AKT/mTOR. These pathways are involved in controlling cellular growth, apoptosis, differentiation, and proliferation, and play a central role in endothelial cell signaling and angiogenesis. Many vascular malformations share similar aberrant molecular signaling pathways with cancers and inflammatory disorders. Therefore, selective anticancer agents and immunosuppressants may be beneficial in treating vascular malformations of specific mutations. The current classification systems of vascular malformations, including the International Society of the Study of Vascular Anomalies (ISSVA) classification, are primarily observational and clinical, and are not based on the molecular pathways involved in the pathogenesis of the condition. Several molecular pathways with potential therapeutic targets have been demonstrated to contribute to the development of various vascular anomalies. Classifying vascular malformations based on their molecular pathogenesis may improve treatment by determining the underlying nature of the condition and their potential therapeutic target.

Extracranial arteriovenous malformations: from bedside to bench

Arteriovenous malformation (AVM) is defined as a fast-flow vascular anomaly that shunts blood from arteries directly to veins. This short circuit of blood flow contributes to progressive expansion of draining veins, resulting in ischaemia, tissue deformation and in some severe cases, congestive heart failure. Various medical interventions have been employed to treat AVM, however, management of which remains a huge challenge because of its high recurrence rate and lethal complications. Thus, understanding the underlying mechanisms of AVM development and progression will help direct discovery and a potential cure. Here, we summarize current findings in the field of extracranial AVMs with the aim to provide insight into their aetiology and molecular influences, in the hope to pave the way for future treatment.

Role of colour-Doppler high-frequency ultrasonography in capillary malformation-arteriovenous malformation syndrome: a case series

High-frequency ultrasonography (HFUS) represents a useful adjunct for dermatologists in the diagnosis of capillary malformation-arteriovenous malformation (CM-AVM) syndrome. We present a paediatric case series of 6 patients with confirmed RASA1 gene mutation in whom HFUS demonstrated AVM beneath cutaneous CM-like lesions greater than 1.5 cm.

Atypical capillary malformations with subsequent diplegia: A difficult case of capillary malformation-arteriovenous malformation syndrome

Capillary malformation-arteriovenous malformation syndrome (CM-AVM) is a rare condition associated with mutations in the genes RASA1 and EPHB4. We present a challenging case of CM-AVM in a 17-month-old boy with permanent diplegia from an undiagnosed arteriovenous malformation underlying a large atypical capillary malformation over the lower thoracic spine. This case demonstrates that clinicians should have a low threshold for neuroimaging in the context of new neurologic symptoms in patients with atypical capillary malformations.

A novel RASA1 mutation causing capillary malformation-arteriovenous malformation (CM-AVM): the first genetic clinical report in East Asia

Capillary malformation-arteriovenous malformation (CM-AVM) is a clinical entity newly identified in 2003 that is caused by mutation of the RASA-1 gene, which encodes the protein p120-RasGAP. To date, most of the clinical reports on CM-AVM in the literature involve samples entirely consisting of Caucasians of European and North American descent, while reports from China or East Asia are few. Here, we describe a genetic clinical report of CM-AVM. Sequencing revealed a novel stop mutation in the RASA-1 gene causing loss of function (LOF) of the RasGAP domain. To our knowledge, this is the first genetic clinical report of a CM-AVM patient in East Asia. This report may extend our understanding and support further studies of CM-AVM in East Asia.

Integrative analysis of oncogenic fusion genes and their functional impact in colorectal cancer

Background

Fusion genes are good candidates of molecular targets for cancer therapy. However, there is insufficient research on the clinical implications and functional characteristics of fusion genes in colorectal cancer (CRC).

Methods

In this study, we analysed RNA sequencing data of CRC patients (147 tumour and 47 matched normal tissues) to identify oncogenic fusion genes and evaluated their role in CRC.

Results

We validated 24 fusion genes, including novel fusions, by three algorithms and Sanger sequencing. Fusions from most patients were mutually exclusive CRC oncogenes and included tumour suppressor gene mutations. Eleven fusion genes from 13 patients (8.8%) were determined as oncogenic fusion genes by analysing their gene expression and function. To investigate their oncogenic impact, we performed proliferation and migration assays of CRC cell lines expressing fusion genes of GTF3A-CDK8, NAGLU- IKZF3, RNF121- FOLR2, and STRN-ALK. Overexpression of these fusion genes increased cell proliferation except GTF3A-CDK8. In addition, overexpression of NAGLU-IKZF3 enhanced migration of CRC cells. We demonstrated that NAGLU-IKZF3, RNF121-FOLR2, and STRN-ALK had tumourigenic effects in CRC.

Conclusion

In summary, we identified and characterised oncogenic fusion genes and their function in CRC, and implicated NAGLU-IKZF3 and RNF121-FOLR2 as novel molecular targets for personalised medicine development.

High-frequency color Doppler ultrasound as the first diagnostic and monitoring choice for early superficial high-flow vascular malformations

Diagnosis and monitoring of early high-flow vascular malformations could be a meaningful pursuit. However, there has been no ideal method for their long-term monitoring and prognosis. We examined 21 early high-flow vascular malformations in this study and deemed that high-frequency color Doppler ultrasound could be regarded as the first diagnostic and monitoring choice for early high-flow vascular malformations at present.

A Typical Vascular and Pigmentary Dermoscopic Pattern of Capillary Malformations in Capillary Malformation-Arteriovenous Malformation Syndrome: Report of Four Cases

We report dermoscopic characteristics of cutaneous capillary malformations in four patients with capillary malformation-arteriovenous malformation (CM-AVM) syndrome. We observed a mixed vascular and pigmentary pattern with branched linear vessels and an underlying homogeneous brown background. Disappearance of the vascular pattern on pressure revealed an underlying faint pigmentary reticular pattern. Our results suggest that this typical biphasic pattern on dermoscopy may be useful for the diagnosis of CM-AVM syndrome.

A spectrum of intracranial vascular high-flow arteriovenous shunts in RASA1 mutations

PURPOSE AND BACKGROUND

We describe three paediatric cases with different intracranial fast-flow shunts presenting early in life, all with capillary malformation-arteriovenous malformation syndrome and RASA1 verified mutations. Intracranial arteriovenous fast-flow shunts are rare vascular malformations typically presenting early in life and have been associated with cutaneous capillary malformations, characterized as capillary malformation-arteriovenous malformation syndrome. Heterozygous RASA1 gene mutations have been found to be disease causing with high penetrance for the typical cutaneous findings, but only some individuals with the syndrome have intracranial lesions.

CASES

One infant presented with a vein of Galen malformation responsible for hydrodynamic disorders, one neonate suffered from severe cardiac insufficiency related to a superior sagittal sinus dural malformation with high-flow fistulas, and one baby was treated at infant age of a choroidal arteriovenous fistula discovered antenatally.

RESULTS AND CONCLUSIONS

We report the follow-up of these three cases with RASA1 gene mutation and comment on the possible role of evaluation for vascular lesions and capillary malformation-arteriovenous malformation syndrome in patients and their families, with intracranial fast-flow shunts.

Mutations in RASA1 and GDF2 identified in patients with clinical features of hereditary hemorrhagic telangiectasia

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant vascular disorder caused by mutations in ENG, ACVRL1 and SMAD4, which function in regulating the transforming growth factor beta and bone morphogenetic protein signaling pathways. Symptoms of HHT can be present in individuals who test negative for mutations in these three genes indicating other genes may be involved. In this study, we tested for mutations in two genes, RASA1 and GDF2, which were recently reported to be involved in vascular disorders. To determine whether RASA1 and GDF2 have phenotypic overlap with HHT and should be included in diagnostic testing, we developed a next-generation sequencing assay to detect mutations in 93 unrelated individuals who previously tested negative for mutations in ENG, ACVRL1 and SMAD4, but were clinically suspected to have HHT. Pathogenic mutations in RASA1 were identified in two samples (2.15%) and a variant of unknown significance in GDF2 was detected in one sample. All three individuals experienced epistaxis with dermal lesions described in medical records as telangiectases. These results indicate that the inclusion of RASA1 and GDF2 screening in individuals suspected to have HHT will increase the detection rate and aid clinicians in making an accurate diagnosis.

Multifocal capillary malformations in an older, asymptomatic child with a novel RASA1 mutation

Multifocal capillary malformation (CM) is the cardinal feature of patients with RASA1 mutations. These CMs are ‘red flags’, signalling the possible association with an arteriovenous malformation (AVM) or an arteriovenous fistula (AVF). We report an 8‐year‐old boy who presented with > 20 CMs, who was found to have a novel mutation in the RASA1 gene. Radiological screening of children with RASA1 mutations is not standardized, and we elected to carry out baseline magnetic resonance imaging of the brain and spine in our case, which gave normal results. We discuss the recent literature and our approach in the management of such a case.

Clinical spectrum of capillary malformation-arteriovenous malformation syndrome presenting to a pediatric dermatology practice: a retrospective study

Capillary malformation-arteriovenous malformation syndrome (CM-AVM) is an autosomal dominant disorder caused by RASA1 mutations. The prevalence and phenotypic spectrum are unknown. Evaluation of patients with multiple CMs is challenging because associated AVMs can be life threatening. The objective of this study was to describe the clinical characteristics of children presenting with features of CM-AVM to an academic pediatric dermatology practice. After institutional review board approval was received, a retrospective chart review was performed of patients presenting between 2009 and 2012 with features of CM-AVM. We report nine cases. Presenting symptoms ranged from extensive vascular stains and cardiac failure to CMs noted incidentally during routine skin examination. All demonstrated multiple CMs, two had Parkes Weber syndrome, and two had multiple infantile hemangiomas. Seven patients had family histories of multiple CMs; three had family histories of large, atypical CMs. Six had personal or family histories of AVMs. Genetic evaluation was recommended for all and was pursued by six families; four RASA1 mutations were identified, including one de novo. Consultations with neurology, cardiology, and orthopedics were recommended. Most patients (89%) have not required treatment to date. CM-AVM is an underrecognized condition with a wide clinical spectrum that often presents in childhood. Further evaluation may be indicated in patients with multiple CMs. This study is limited by its small and retrospective nature.

[What’s new in pediatric dermatology?]

This article is a selection of the most significant developments in the field of pediatric dermatology through an analysis of the articles published between October 2012 and October 2013. In the field of vascular anomalies, propranolol remains a topic of interest for infantile hemangiomas. New clinical concepts appear in the field of vascular malformations in parallel to genetic progress in this area. New epidemiological data or new pathophysiological concepts apply to atopic dermatitis. Congenital or atypical nevi of the child benefit from genetic progress or improvement of clinical knowledge. Although rare, melanoma of the child concerns by its increasing incidence and its misleadingclinical characteristics. Other data reported here relate to infectious skin of the child, morpheas, neurofibromatosis type 1, psoriasis and other commonly seen dermatoses in children.