Verrucous Venous Malformation-Subcutaneous Variant

Vascular Malformations

Vascular malformations are intricate anomalies of the circulatory system, presenting a diverse array of clinical manifestations, and posing significant challenges in diagnosis and treatment. The pathogenesis of vascular malformations is explored through the lens of genetic and molecular mechanisms, shedding light on the pivotal role of somatic mutations and dysregulated signaling pathways. Clinical presentations of vascular malformations are widely variable, ranging from cosmetic concerns to life-threatening complications. The utility of imaging techniques, such as magnetic resonance imaging (MRI), computed tomography (CT), and angiography, are discussed in detail, emphasizing their role in precise delineation and characterization. Therapeutic strategies for vascular malformations are multifaceted, considering factors such as lesion size, location, potential complications, and patient-specific factors. Traditional interventions, including surgical excision and embolization, are appraised alongside emerging approaches like targeted molecular therapies and minimally invasive procedures. The manuscript underscores the need for an individualized treatment approach, optimizing outcomes while minimizing risks and complications. In summation, this manuscript offers a comprehensive analysis of vascular malformations, encompassing their underlying pathogenesis, clinical nuances, diagnostic methods, and therapeutic considerations. By synthesizing current knowledge and highlighting gaps in understanding, this review serves as a valuable resource for clinicians, researchers, and medical practitioners, fostering an enhanced comprehension of vascular malformations and paving the way for improved patient care and innovative research endeavors.

Immunohistochemical Expression of Lymphatic Endothelial Markers in Blue Rubber Bleb Nevus Syndrome

INTRODUCTION

Blue rubber bleb nevus syndrome (BRBNS) is an uncommon vascular anomaly characterized by multifocal cutaneous, visceral, and other soft tissue or solid organ venous malformations. We observed that BRBNS lesions express immunohistochemical markers of lymphatic differentiation.

METHODS

BRBNS histopathologic specimens assessed at our institution during the past 27 years were reviewed. Slides from 19 BRBNS lesions were selected from 14 patients (9 cutaneous, 9 gastrointestinal, and 1 hepatic). We recorded the involved anatomical compartments and presence/absence of thrombi or vascular smooth muscle. Immunohistochemical endothelial expression of PROX1 (nuclear) and D2-40 (membranous/cytoplasmic) was evaluated semi-quantitatively.

RESULTS

Endothelial PROX1 immunopositivity was noted in all specimens; the majority (89.5%) demonstrated staining in more than 10% of cells. D2-40 immunopositivity was present in one-third (33%) of cutaneous lesions and only 1 gastrointestinal lesion.

CONCLUSION

Endothelial cells in BRBNS almost always express 1 or more immunohistochemical markers of lymphatic differentiation.

Usefulness of Ultrasound in Verrucous Venous Malformation: a Series of 103 Cases

BACKGROUND

Verrucous venous malformation (VVM), previously called "verrucous hemangioma," is a rare type of vascular malformation.

OBJECTIVE

Little is known about the ultrasonographic characteristics of VVM. The present study aimed to show the conventional US and elastographic features of a VVM.

MATERIALS AND METHODS

The US findings in 103 patients with VVMs were retrospectively evaluated.

RESULTS

On gray-scale ultrasound images, 98 (95.1%) lesions showed subcutaneous fat infiltration from skin across muscle to deep fascia. The other 5 (4.9%) sat in the subcutaneous layer with no skin involvement. Most (96.1%) lesions were hyperechoic. Furthermore, 71.8% of lesions were heterogeneous, 68.9% of which were with ill-defined margins. Calcifications and visible vessels were present in 5.7% and 10.7% of the VVM cases, respectively. By color Doppler ultrasound, all lesions were found with low vascular density and 4.9% showed enhanced blood flow after compression. Venous spectrum was observed in 67.0% of lesions. The elasticity score was 2.66 ± 0.48.

CONCLUSION

Diagnosis of a VVM is challenging in the clinic. However, we found that most VVM lesions present distinctive ultrasound imaging characteristics. These ultrasound findings may well contribute to the accuracy of VVM diagnosis, especially in those with the absence of epidermal changes and the lack of dermal involvement.

Somatic mutation spectrum of a Chinese cohort of pediatrics with vascular malformations

BACKGROUND

Somatic mutations of cancer driver genes are found to be responsible for vascular malformations with clinical manifestations ranging from cutaneous birthmarks to life-threatening systemic anomalies. Till now, only a limited number of cases and mutations were reported in Chinese population. The purpose of this study was to describe the somatic mutation spectrum of a cohort of Chinese pediatrics with vascular malformations.

METHODS

Pediatrics diagnosed with various vascular malformations were collected between May 2019 and October 2020 from Beijing Children's Hospital. Genomic DNA of skin lesion of each patient was extracted and sequenced by whole-exome sequencing to identify pathogenic somatic mutations. Mutations with variant allele frequency less than 5% were validated by ultra-deep sequencing.

RESULTS

A total of 67 pediatrics (33 males, 34 females, age range: 0.1-14.8 years) were analyzed. Exome sequencing identified somatic mutations of corresponding genes in 53 patients, yielding a molecular diagnosis rate of 79.1%. Among 29 PIK3CA mutations, 17 were well-known hotspot p.E542K, p.E545K and p.H1047R/L. Non-hotspot mutations were prevalent in patients with PIK3CA-related overgrowth spectrum, accounting for 50.0% (11/22) of detected mutations. The hotspot GNAQ p.R183Q and TEK p.L914F mutations were responsible for the majority of port-wine stain/Sturge-Weber syndrome and venous malformation, respectively. In addition, we identified a novel AKT1 p.Q79K mutation in Proteus syndrome and MAP3K3 p.E387D mutation in verrucous venous malformation.

CONCLUSIONS

The somatic mutation spectrum of vascular malformations in Chinese population is similar to that reported in other populations, but non-hotspot PIK3CA mutations may also be prevalent. Molecular diagnosis may help the clinical diagnosis, treatment and management of these pediatric patients with vascular malformations.

Thoracic venous malformation: a particular form of a visceral variant

A teenage boy was admitted due to a thoracic mass with previous respiratory infections. The CT scan showed phleboliths in a cystic lesion with large draining channels. He also presented a mild thrombocytosis, elevated fibrinogen and D-dimer. Arteriogram revealed no abnormal arterial supply but venography proved venous draining channels as the major components of the lesion. The most important venous pedicle was embolised. However, 6 months later, CT scan showed no reduction in lesion size. Surgical resection was performed. Anatomopathological study described a venous malformation (VM) with a lymphatic component, and genetic testing found a typical mutation in PIK3CA and genetic variant in MAP3K3 This case reports a very rare pattern of thoracic vascular tumour. The authors aim to highlight the importance of genetic studies of VM with atypical presentation in order to achieve a definitive diagnosis.

Verrucous venous malformation with thrombocytopenia in a neonate

Verrucous venous malformations (VVM) are rare, congenital, slow-flow vascular anomalies that have been historically difficult to characterize due to clinical mimics and unclear histological evaluation. A life-threatening complication of VVMs is localized intravascular coagulation. Herein, we describe a male neonate who presented with a congenital VVM on the left lower extremity with associated severe thrombocytopenia. We discuss the multifaceted diagnostic approach used to identify this VVM, while highlighting the use of WT-1 as a negative predictive marker; we additionally outline novel treatment options and management beyond cutaneous involvement.

Venous Malformations in Childhood: Clinical, Histopathological and Genetics Update

Our knowledge in vascular anomalies has grown tremendously in the past decade with the identification of key molecular pathways and genetic mutations that drive the development of vascular tumors and vascular malformations. This has led us to better understand the pathogenesis of vascular lesions, refine their diagnosis and update their classification while also exploring the opportunity for a targeted molecular treatment. This paper aims to provide an overview of venous malformations (VM) in childhood. Specific entities include common VMs, cutaneo-mucosal VM, blue rubber bleb nevus syndrome or Bean syndrome, glomuvenous malformation, cerebral cavernous malformation, familial intraosseous vascular malformation and verrucous venous malformation. The clinicopathological features and the molecular basis of each entity are reviewed.