Vascular Anomalies

Advancing randomized controlled trials of vascular anomalies: an analysis of trial waste

A series of randomized controlled trials (RCTs) have advanced the therapeutic approaches for vascular anomalies (VA). However, a notable obstacle in applying the findings of these trials to real-world patient care is trial waste (TW). To date, the extent of TW in RCTs for VA is not clear. In June 2024, we searched the ClinicalTrials database using the entity names defined by ISSVA classification as search terms. We documented the data available and then explored PubMed and Scopus for the publication status. Reporting adequacy was evaluated using the CONSORT checklist. Design limitations were analyzed based on bias risk and whether the article referenced a relevant systematic review. One hundred fifty-nine RCTs met the inclusion criteria. The majority of RCTs focused on benign VA (81.1%) and utilized pharmacotherapy (79.9%). Over 90% of these trials were conducted in North America, Europe, and Asia as single-center studies (68.6%), with funding primarily from official institutions (83.7%). The analysis of TW excluded 61 RCTs completed after June 2020 that remained unpublished. Among the remaining 98 RCTs, 53 were published, 41 had adequate reporting, and 16 had design limitations. In total, 67 RCTs exhibited at least one characteristic of TW. The 31 RCTs without waste tended to enroll more participants (P = 0.014) and conduct studies across multiple centers (P < 0.001) and countries (P = 0.022). Multicenter participation (P = 0.028) emerged as an independent protective factor against TW.

CONCLUSION

We delineated the features of 159 VA RCTs and revealed that 68.4% of them exhibited TW. The diverse traits of the different TW indicators identified could serve as valuable insights for conducting future VA RCTs more rationally and efficiently.

WHAT IS KNOWN

• Currently, a number of RCTs have been conducted on vascular anomalies (VA). However, there has been no study analyzing the situation of trial waste in VA-related RCTs.

WHAT IS NEW

• This study is the first to describe the characteristics of VA-related RCTs globally over the past 20 years and has identified a high burden of trial waste in this field. Multicenter participation was an independent protective factor against trial waste.

Identification of Potential Therapeutics for Infantile Hemangioma via in silico Investigation and in vitro Validation

Introduction

Infantile Hemangioma (IH) is a prevalent benign vascular tumor affecting approximately 5-10% of infants. Its underlying pathogenesis remains enigmatic, and current therapeutic approaches show limited effectiveness. Our study aimed to discover potential IH-associated therapeutics through a transcriptomic, computational drug repurposing methodology.

Methods

Utilizing the IH-specific dataset GSE127487 from the Gene Expression Omnibus, we identified differentially expressed genes (DEGs) and conducted weighted gene coexpression network analysis (WGCNA). Subsequently, a protein-protein interaction (PPI) network was constructed to obtain the top 100 hub genes. Drug candidates were sourced from the Connectivity Map (CMap) and Comparative Toxicogenomics Database (CTD).

Results

Our analysis revealed 1203 DEGs and a significant module of 1780 mRNAs strongly correlated with IH. These genes were primarily enriched in the PI3K/AKT/MTOR, RAS/MAPK, and CGMP/PKG signaling pathway. After creating a PPI network of overlapping genes, we filtered out the top 100 hub genes. Ultimately, 44 non-toxic drugs were identified through the CMap and CTD databases. Twelve molecular-targeting agents (belinostat, chir 99021, dasatinib, entinostat, panobinostat, sirolimus, sorafenib, sunitinib, thalidomide, U 0126, vorinostat, and wortmannin) may be potential candidates for IH therapy. Moreover, in vitro experiments demonstrated that entinostat, sorafenib, dasatinib, and sirolimus restricted the proliferation and migration and initiated apoptosis in HemEC cells, thereby underscoring their potential therapeutic value.

Conclusion

Our investigation revealed that the pathogenic mechanism underlying IH might be closely associated with the PI3K/AKT/MTOR, RAS/MAPK, and CGMP/PKG signaling pathways. Furthermore, we identified twelve molecular-targeting agents among the predicted drugs that show promise as therapeutic candidates for IH.

A systematic review of Bannayan - Riley - Ruvalcaba syndrome

Bannayan-Riley-Ruvalcaba syndrome (BRRS) is a rare overgrowth condition caused by a pathogenic variant in the phosphatase and tensin homolog (PTEN) gene and belongs to a group of disorders called PTEN hamartoma tumor syndrome (PHTS). The diagnosis is often complicated by great phenotypic diversity. Furthermore, to this date treatment options are limited. Here we performed a systematic review using PubMed, Cochrane, and Scopus databases to identify cases of pediatric patients diagnosed with BRRS and summarized information about the clinical presentation, treatment, and long-term patient care. A total of 83 pediatric patients with BRRS were identified. The most common clinical findings were macrocephaly (77%) and developmental disorders (63%). Surgical interventions were the treatment of choice, described in 19 articles. Patient surveillance was proposed in 15 case reports and mostly aimed at periodic cancer screening. Recognition of BRRS clinical symptoms and early referral to a geneticist is important for better disease control and overall prognosis. As targeted treatment is still lacking, symptom relief and long-term surveillance remain the main management strategies.

Phase II Study of Samotolisib in Children and Young Adults With Tumors Harboring Phosphoinositide 3-Kinase/Mammalian Target of Rapamycin Pathway Alterations: Pediatric MATCH APEC1621D

PURPOSE

Patients age 1-21 years with relapsed or refractory solid and CNS tumors were assigned to phase II studies of molecularly targeted therapies on the National Cancer Institute-Children's Oncology Group (NCI-COG) Pediatric Molecular Analysis for Therapy Choice (MATCH) trial. Patients whose tumors harbored predefined genetic alterations in the phosphoinositide 3-kinase (PI3K)/mammalian target of rapamycin (mTOR) pathway and lacked mitogen-activated protein kinase pathway activating alterations were treated with the PI3K/mTOR inhibitor samotolisib.

METHODS

Patients received samotolisib twice daily in 28-day cycles until disease progression or unacceptable toxicity. A rolling 6 limited dose escalation was performed as, to our knowledge, this was the first pediatric study of samotolisib. The primary end point was the objective response rate; secondary end points included progression-free survival (PFS) and the recommended phase II dose and toxicity of samotolisib in children.

RESULTS

A total of 3.4% (41/1,206) of centrally tested patients were matched to this arm. Seventeen patients were treated. Among treated patients, the most common diagnoses included osteosarcoma (n = 6) and high-grade glioma (n = 5) harboring alterations in phosphatase and tensin homolog (n = 6), PIK3CA (n = 5), and tuberous sclerosis complex 2 (n = 3). No objective responses or prolonged stable disease were observed. Three-month PFS was 12% (95% CI, 2 to 31). Two patients experienced dose-limiting toxicities (mucositis and pneumonitis). Dose level 2 (115 mg/m2/dose twice daily) was determined to be the recommended phase II dose of samotolisib in children.

CONCLUSION

This nationwide study was successful at identifying patients and evaluating the efficacy of molecularly targeted therapy for rare molecular subgroups of patients in a histology-agnostic fashion. Unfortunately, there was no activity of samotolisib against tumors with PI3K/mTOR pathway alterations. Prospective trials such as the NCI-COG Pediatric MATCH are necessary to evaluate the efficacy of molecularly targeted therapies given their increasing use in clinical practice.

CT Angiography for Aortic Arch Anomalies: Prevalence, Diagnostic Efficacy, and Illustrative Findings

Aortic arch anomalies encompass a diverse spectrum of conditions. Elucidating the prevalence of these anomalies, their impact on patient wellbeing, and the most effective diagnostic tools are crucial steps in ensuring optimal patient care. This paper aims to explore the various presentations of aortic arch anomalies, emphasizing the remarkable utility of computed tomography (CT) angiography in their definitive diagnosis and characterization. We conducted a retrospective study on patients who were submitted to the CT angiography of the thoracic aorta or supra-aortic trunks, or the contrast-enhanced CT scans of the thorax and/or cervical region between January 2021 and February 2024 in our Hospital. Out of the total of 2350 patients, 18 were diagnosed with aortic arch anomalies, with an average age of approximately 55 years. The aortic arch anomalies identified in the study were as follows: left aortic arch with the aberrant origin of the right subclavian artery, right aortic arch (types I and II), double aortic arch, aortic coarctation, aortic pseudocoarctation, and ductus diverticulum. Although often asymptomatic, aortic arch anomalies require recognition and CT using advanced post-processing techniques is the optimal diagnostic method with the ability to also identify other associated cardiac or vascular malformations.

Dyadic coping experiences of parents of children with vascular anomalies

BACKGROUND

Vascular anomalies (VAs) are a spectrum of rare pediatric disorders that require coordinated care from multiple subspecialists. Parents often struggle to coordinate care for their child's complex rare disorder. Even when they do access expert care, parents of children with VAs report high levels of stress and uncertainty. While previous research has explored parents' experiences navigating care for VAs, we know very little about how parents cope with stress together. Given the effect that dyadic coping can have on individual, couple, family, and child outcomes, we aimed to gain a better understanding of dyadic coping in the context of VAs.

PROCEDURES

We collected data using semi-structured interviews with 27 parents (13 dyads and one individual parent). Data were analyzed using dyadic thematic analysis.

RESULTS

Parents experienced stress related to medical, personal, logistical, and financial aspects of their child's healthcare. They relied on eight coping strategies: active coping, seeking emotional support, seeking informational support, cognitive avoidance, distraction, cognitive reframing, acceptance, and internalization. When analyzed together, we found evidence of five dyadic coping dynamics: collaborative, supportive, delegated, separate, and negative.

CONCLUSION

Dyadic coping is complex and multilayered for parents of children with VAs. While the child's diagnosis is considered a shared stressor, both parents may not share preferred coping strategies. Parents of the same child may also be coping with different medical, relational/social, personal, or logistical stressors altogether. Psychosocial interventions designed to facilitate parental coping should address these complex coping dynamics.

A multi-step approach to overcome challenges in the management of head and neck lymphatic malformations, and response to treatment

BACKGROUND

Lymphatic malformations are vascular developmental anomalies varying from local superficial masses to diffuse infiltrating lesions, resulting in disfigurement. Patients' outcomes range from spontaneous regression to severe sequelae notwithstanding appropriate treatment. The current classification guides, in part, clinicians through the decision-making process, prognosis prediction and choice of therapeutic strategies. Even though the understanding of molecular basis of the disease has been recently improved, a standardized management algorithm has not been reached yet.

RESULTS

Here, we report our experience on five children with different lymphatic anomalies of the head and neck region treated by applying a multidisciplinary approach reaching a consensus among specialists on problem-solving and setting priorities.

CONCLUSIONS

Although restitutio ad integrum was rarely achieved and the burden of care is challenging for patients, caregivers and healthcare providers, this study demonstrates how the referral to expert centres can significantly improve outcomes by alleviating parental stress and ameliorating patients' quality of life. A flow-chart is proposed to guide the multidisciplinary care of children with LMs and to encourage multidisciplinary collaborative initiatives to implement dedicated patients' pathways.

Therapy with sirolimus in vascular anomalies: the experience of two Italian centers on 14 pediatric patients

Introduction

Vascular anomalies (VAs) constitute a heterogeneous group of tumors and malformations capable of inducing significant clinical events in specific patients, such as the compression of vital organs, pain, functional impairment, or acquired coagulopathy. Molecular investigations into the underlying mechanisms of VAs have unveiled the frequent involvement of the PI3 K/AKT/mTOR pathway. Sirolimus, a specific mTOR inhibitor, has emerged as a potential therapeutic agent; however, its routine clinical application in complex VAs is currently restricted by a lack of extensive clinical experience.

Methods

Between 2015 and 2024, we administered sirolimus to 14 pediatric patients with various types of vascular anomalies in two Italian centers, subjecting them to clinical and instrumental follow-up to investigate its efficacy and the possible occurrence of adverse events.

Results

An overall improvement in or stability of their vascular anomalies was reported by 86% of patients. We also assessed toxicity, noting a low prevalence of life-threatening adverse events: only one case of sepsis was reported in a patient with a severe clinical condition, and four cases of recurrent aphthosis (28%) were reported. The most common side effect was dyslipidemia, with 43% of patients developing hypercholesterolemia (21%) or hypertriglyceridemia (21%), although these patients generally did not reach severe levels.

Discussion

In line with data in the literature, according to our experience, medical therapy with sirolimus should be considered in pediatric patients affected by vascular anomalies.

Australian healthcare professionals' perspectives on genetic counseling and genetic diagnosis in vascular anomalies

Genomic technologies are now utilized for the genetic diagnosis of vascular anomalies. This provides the opportunity for genetic counselors to make a significant contribution to patient care for this complex disease. The aim of this study was to explore Australian healthcare professionals' perspectives on the relatively recent integration of molecular diagnostic testing for vascular anomalies, with or without genetic counseling support. Nine semi-structured interviews were conducted with Australian healthcare professionals involved in the provision of care for individuals with vascular anomalies. Thematic analysis identified six themes: (1) Molecular diagnosis is beneficial; (2) psychosocial needs can motivate families to pursue a molecular diagnosis; (3) molecular genetic testing for vascular anomalies is complex; (4) genetic service provision is not a one size fits all; (5) a client-centered approach for genetic service provision can go a long way; and (6) the value of genetic counselors. Based on our findings, implementation of a vascular anomalies genetic diagnostic program inclusive of genetic counseling may be challenging, yet such programs are likely to benefit both patients and their families, as well as healthcare professionals. As this paradigm shift unfolds, genetic counselors have an opportunity to contribute to the vascular anomaly field by educating healthcare professionals and patients, by participating in multidisciplinary clinics to support complex cases and by raising awareness regarding their practice and potential contributions.

Targeted treatment in complex lymphatic anomaly: a case of synergistic efficacy of trametinib and sirolimus

Repurposing anticancer drugs to vascular malformations has significantly improved patient outcomes. Complex Lymphatic Anomalies (CLA) are part of the spectrum of lymphatic malformations (LMs) that share similar oncogenic mutations to cancer. We report the case of a young patient with highly symptomatic CLA who was initially treated with sirolimus, due to the frequent involvement of the PI3K-AKT-mTOR pathway in CLA pathogenesis. Despite an initial reduction in symptoms, sirolimus progressively lost its effectiveness. After an unsuccessful attempt with trametinib alone, sirolimus was added to trametinib and resulted in a significant, rapid and sustained improvement in symptoms. This suggests that, contrary to current dogmas, combination therapy using sub-therapeutic doses targeting both the PI3K and RAS pathways retains efficacy without generating the toxicity known for combination therapies, and is beneficial in the management of CLAs and potentially other vascular anomalies.

The role of primary care in rare disorders: A qualitative study of parents and patients managing complex vascular anomalies

Background

Patients with complex rare disorders often require the care of multiple specialists. Effective coordination between primary and specialty care is needed to ensure patients receive high-quality care. Previous research has documented the importance of primary care clinicians providing referrals to specialty care and the importance of specialists in helping patients reach a diagnosis. However, little is known about primary care clinicians' roles in the ongoing care of patients with rare disorders. In the current study, we explored the role of primary care clinicians in the care of rare and complex vascular anomalies.

Materials and Methods

Data were collected using semi-structured qualitative interviews with 34 parents and 25 adult patients recruited from advocacy groups for patients with complex vascular anomalies participated. We asked participants about their diagnosis, care experiences, and communication with clinicians. We used thematic analysis to identify themes illustrating the roles of primary care clinicians.

Results

PCC roles were characterized by four behaviors. Supporting behaviors included learning more about vascular anomalies and asking participants about the care they received from specialists. Facilitating included providing referrals, ordering tests, and engaging in problem-solving. Interfering included failing to provide referrals or help participants coordinate care, ordering incorrect tests, or making inappropriate recommendations. Disregarding included focusing narrowly on primary care needs and not showing concern about the vascular anomaly.

Conclusions

The results reveal opportunities to improve primary care for patients with vascular anomalies. Disregarding and interfering behaviors furthered the division between primary and specialty care for patients with vascular anomalies and prevented patients from receiving comprehensive primary care. Supporting and facilitating behaviors convey genuine interest in the care of the vascular anomaly and a commitment to helping the patient and parent.

Central conducting lymphatic anomaly: from bench to bedside

Central conducting lymphatic anomaly (CCLA) is a complex lymphatic anomaly characterized by abnormalities of the central lymphatics and may present with nonimmune fetal hydrops, chylothorax, chylous ascites, or lymphedema. CCLA has historically been difficult to diagnose and treat; however, recent advances in imaging, such as dynamic contrast magnetic resonance lymphangiography, and in genomics, such as deep sequencing and utilization of cell-free DNA, have improved diagnosis and refined both genotype and phenotype. Furthermore, in vitro and in vivo models have confirmed genetic causes of CCLA, defined the underlying pathogenesis, and facilitated personalized medicine to improve outcomes. Basic, translational, and clinical science are essential for a bedside-to-bench and back approach for CCLA.

[Management of pediatric vascular malformations]

BACKGROUND

Vascular malformations belong to the group of vascular anomalies. They are rare congenital diseases resulting from abnormal development of vessels and can arise in any location, often in the head and neck region. Clinical symptoms are variable, functional handicaps and esthetic problems may result.

MATERIALS AND METHODS

One differentiates between arteriovenous, lymphatic, venous, and capillary malformations and combinations thereof. Their classification, symptoms, diagnostics, and treatment options are discussed.

RESULTS

The different types of vascular malformations as well as their clinical presentation, diagnostic workup, and therapeutic options are presented, supported by clinical examples.

CONCLUSION

Interdisciplinary care of pediatric patients with vascular malformations is essential in order to generate a treatment concept after correct diagnosis and improve symptoms and quality of life.

Understanding hereditary hemorrhagic telangiectasia: From genetic anomalies to systemic manifestations, quality of life, and epistaxis management-Exploring the otolaryngologist's integral role

Hereditary hemorrhagic telangiectasia (HHT), also known as Osler-Rendu-Weber syndrome, is a rare autosomal dominant disorder characterized by vascular malformations. This comprehensive review aimed to provide an overview and summarize various aspects of HHT, including the genetic abnormalities, complications associated with visceral arteriovenous malformations (AVMs), prognosis of HHT, quality of life (QOL), and treatment of epistaxis. In addition, this review highlights the challenges in diagnosing HHT and emphasizes the critical role of otolaryngologists in the early detection of HHT. Otolaryngologists can refer patients with refractory epistaxis for AVM screening to expedite intervention. Mutation of the genes involved in the transforming growth factor-β signaling pathway leads to the incidence of HHT, resulting in the formation of abnormal blood vessel formation. These vascular malformations commonly manifest as telangiectasia on the skin and mucous membranes; however, epistaxis remains the hallmark symptom of HHT. The impact of HHT goes beyond the visible symptoms and often includes the formation of life-threatening visceral AVMs in the lungs, liver, and brain. The prognosis of patients with HHT is closely related to the development of these complications, necessitating timely diagnosis and intervention. Refractory epistaxis diminishes the QOL of patients with HHT. The management of epistaxis ranges from conservative measures to advanced interventions such as prevention, conservative treatments, ablation, surgical procedures, and the administration of anti-angiogenic agents. However, effective management requires a multidisciplinary approach. The diagnosis of HHT remains challenging due to its variable presentation and lack of awareness among physicians. This review highlights the importance of reducing the duration between symptom onset and diagnosis. Otolaryngologists who are experienced in the management of refractory epistaxis can aid in identifying potential cases of HHT. They can facilitate the initiation of screening for visceral AVMs via prompt recognition of the signs and symptoms of HHT, contributing to improved patient outcomes. Early detection and intervention through screening can extend the life expectancy of patients with HHT to levels comparable with that of the general population. In conclusion, this review provides insight into various aspects of HHT and emphasizes the importance of timely diagnosis and intervention in the mitigation of the potentially life-threatening complications associated with this disorder. Otolaryngologists play a critical role in this process, serving as gatekeepers to the identification of cases of HHT and implementation of appropriate screening and management pathways, thereby improving the life expectancy and QOL of patients.

Lymphatic malformations: mechanistic insights and evolving therapeutic frontiers

The lymphatic vascular system is gaining recognition for its multifaceted role and broad pathological significance. Once perceived as a mere conduit for interstitial fluid and immune cell transport, recent research has unveiled its active involvement in critical physiological processes and common diseases, including inflammation, autoimmune diseases, and atherosclerosis. Consequently, abnormal development or functionality of lymphatic vessels can result in serious health complications. Here, we discuss lymphatic malformations (LMs), which are localized lesions that manifest as fluid-filled cysts or extensive infiltrative lymphatic vessel overgrowth, often associated with debilitating, even life-threatening, consequences. Genetic causes of LMs have been uncovered, and several promising drug-based therapies are currently under investigation and will be discussed.

Treatment practices and response in kaposiform hemangioendothelioma: A multicenter cohort study

BACKGROUND AND OBJECTIVES

Kaposiform hemangioendothelioma (KHE) and tufted angioma (TA) are rare vascular tumors in children historically associated with significant morbidity and mortality. This study was conducted to determine first-line therapy in the absence of available prospective clinical trials.

METHODS

Patients from 17 institutions diagnosed with KHE/TA between 2005 and 2020 with more than 6 months of follow-up were included. Response rates to sirolimus and vincristine were compared at 3 and 6 months. Durability of response and response to other treatment modalities were also evaluated.

RESULTS

Of 159 unique KHE/TA subjects, Kasabach-Merritt phenomenon (KMP) was present in 64 (40.3%), and only two patients were deceased (1.3%). Over 60% (n = 96) demonstrated treatment response at 3 months, and more than 70% (n = 114) by 6 months (no significant difference across groups). The vincristine group had higher radiologic response at 3 months compared to sirolimus (72.7% vs. 20%, p = .03), but there were no differences between these groups at 6 months. There were no differences in rates of recurrent or progressive disease between vincristine and sirolimus.

CONCLUSIONS

In this large, multicenter cohort of 159 patients with KHE/TA, rates of KMP were consistent with historical literature, but the mortality rate (1.3%) was much lower. Overall treatment response rates were high (>70%), and there was no significant difference in treatment response or durability of disease comparing sirolimus to vincristine. Our results support individualized treatment decision plans depending on clinical scenario and patient/physician preferences. Response criteria and response rates reported here will be useful for guiding future treatment protocols for vascular tumors.

Mental and physical health of adult patients affected by complex vascular anomalies

OBJECTIVE

We examined care and communication factors that affect physical and mental health for patients with complex vascular anomalies (VAs).

METHODS

VA patients (N = 135) completed an online survey with measures of ability to navigate healthcare, quality of information exchange, perceived stigma, and demographic variables. We performed linear regression to determine if these variables were associated with mental and physical health.

RESULTS

Physical and mental health were associated with information exchange (β = .41, 95% CI=.12 -.69; β = .33, 95% CI=.04 -.62), stigma (β = -.49, 95% CI=-.74 to -.24; β = -.63, 95% CI=-.89 to -.38), and education (β = 4.00, 95% CI=.63 - 7.38; β = 3.44, 95% CI=.06 to 6.82). Ability to navigate healthcare was associated with health outcomes in our bivariate model, but not significant in a multivariate model.

CONCLUSION

The results underscore the importance of effective information exchange. Poor information exchange was associated with worse physical and mental health. VA patients with lower education levels and higher perceived stigma reported poorer health outcomes and likely face many struggles accessing care.

PRACTICE IMPLICATIONS

Patient-centered information exchange between clinicians and patients is needed to address unmet information needs. Clinicians can also reduce perceived stigma by validating patients, and should provide resources to reduce disparities related to education.

Alpelisib: A Novel Agent for PIK3CA-Related Overgrowth Spectrum

The aim of this review is to present the information a clinician will need when considering alpelisib therapy for a patient diagnosed with PIK3CA-related overgrowth spectrum (PROS). PROS is a condition caused by a somatic recessive gain-of-function mutation in the gene encoding phosphatidylinositol-3-kinase (PI3K). PROS is rare, affecting approximately 14 births per 1 million. PROS affects many different tissues including skin, bone, vascular, adipose, and connective tissues, thus its presentations vary widely. The presentation of PROS is often described as mosaic, as the disease typically does not affect all cells in the body. For patients two years of age and older requiring systemic therapy, alpelisib is an option which was recently granted accelerated approval by the US Food and Drug Administration (FDA) on April 5, 2022. Alpelisib is an inhibitor of PI3K, slowing the progression of existing lesions and preventing new lesions in patients with PROS. Important drug interactions exist with both CYP3A4 inducers and CYP2C9 substrates. Additionally, providers of patients receiving alpelisib should be aware of potential side effects including hypersensitivity, severe cutaneous adverse reactions, hyperglycemia, pneumonitis, diarrhea, and embryo-fetal toxicity. Despite the potential for adverse events, alpelisib has provided clinical benefit to many patients with PROS as evidenced by the current literature. This review collects and summarizes the currently available evidence, including a recently published case series and multiple case reports. Alpelisib is a promising new option for patients with PROS.

Impact of puberty on procedure frequency for treatment of simple head and neck lymphatic and venous malformations

OBJECTIVE

Puberty has been shown to accelerate growth of vascular malformations, including lymphatic (LM) and venous malformations (VM). This study aims to compare the number of procedures performed before and after puberty in patients with LM and VM to assess whether the onset of puberty results in higher treatment frequency.

METHODS

A retrospective review of head and neck LM and VM patients who were evaluated between January 2009 and December 2019 was performed. Patient demographics, lesion characteristics, and procedural details were recorded. For the purposes of this study, 11 years or older in females and 12 years or older in males were the established cut-offs for the onset of puberty.

RESULTS

After initial screening of 357 patients, 83 patients were included in the study based on inclusion criteria. There were 34 patients with LM (41 %) and 49 with VM (59 %). The mean age at diagnosis was 6.1 ± 10.9 years (LM: 4.2 ± 7.0, VM: 7.4 ± 12.9, p = 0.489). 68 patients underwent treatments, which included sclerotherapy, surgical excision, and/or laser. For all patients, the average number of lifetime treatments when initiated before puberty was 3.78 ± 2.81 and when initiated after puberty was 2.17 ± 1.37 (p = 0.022). Patients diagnosed pre-puberty were more likely to undergo treatments vs. those diagnosed after puberty (OR 10.00, 95 % CI: 2.61-38.28, p < 0.001).

CONCLUSION

We found that the number of treatments was fewer in those who started treatment after puberty. This finding suggests that providers may elect to proceed with observation in asymptomatic patients, given that waiting until after the onset of puberty has not shown an increase in the procedural load on patients.

CDK6-mediated endothelial cell cycle acceleration drives arteriovenous malformations in hereditary hemorrhagic telangiectasia

Increased endothelial cell (EC) proliferation is a hallmark of arteriovenous malformations (AVMs) in hereditary hemorrhagic telangiectasia (HHT). The underlying mechanism and disease relevance of this abnormal cell proliferative state of the ECs remain unknown. Here, we report the identification of a CDK6-driven mechanism of cell cycle progression deregulation directly involved in EC proliferation and HHT vascular pathology. Specifically, HHT mouse liver ECs exhibited defects in their cell cycle control characterized by a G1/S checkpoint bypass and acceleration of cell cycle speed. Phosphorylated retinoblastoma (p-RB1)-a marker of G1/S transition through the restriction point-significantly accumulated in ECs of HHT mouse retinal AVMs and HHT patient skin telangiectasias. Mechanistically, ALK1 loss of function increased the expression of key restriction point mediators, and treatment with palbociclib or ribociclib, two CDK4/6 inhibitors, blocked p-RB1 increase and retinal AVMs in HHT mice. Palbociclib also improved vascular pathology in the brain and slowed down endothelial cell cycle speed and EC proliferation. Specific deletion of Cdk6 in ECs was sufficient to protect HHT mice from AVM pathology. Thus, CDK6-mediated endothelial cell cycle acceleration controls EC proliferation in AVMs and is a central determinant of HHT pathogenesis. We propose that clinically approved CDK4/6 inhibitors have repurposing potential in HHT.

Pediatric vascular anomalies in Austria. Where are we at? A survey among primary care pediatricians

Introduction

Vascular anomalies (VAs) are rare conditions and affected patients often experience a difficult patient journey. Timely diagnosis is only possible if primary caregivers are aware of the anomalies and are connected with dedicated specialists. Aim of our survey was to investigate the knowledge about diagnostic and therapeutic possibilities for children with VAs, and the existing networking among primary pediatric caregivers in Austria.

Methods

Primary care pediatricians in Austria were invited to complete an online questionnaire consisting of 28 questions focusing on pediatric VAs.

Results

Out of 373 invited pediatricians 93 (25%) returned the questionnaires, 86 of which were complete. Most physicians (39/93 42%) answered that they see between 15 and 30 patients with infantile hemangiomas per year. Vascular malformations are rarely treated in the primary care setting; most primary care pediatricians (58/86, 67%) reported that they currently treat fewer than 5 patients with such type of VAs. There was unequivocal agreement among the participants (84/86, 98%) on the need to establish a network of specialists and a registry dedicated to pediatric VAs.

Conclusions

This survey represents the first study shedding light on the awareness of VAs among Austrian pediatricians and can serve as a basis for future investigations and advances in the management of these conditions in Austria and other countries with a similar healthcare setting.

Refractory kaposiform lymphangiomatosis relieved by splenectomy

Introduction

Kaposiform lymphangiomatosis (KLA) is a rare and complex lymphatic anomaly with a poor prognosis. There is no standard treatment, and drug therapies are the most common therapeutic method. However, some patients' symptoms become gradually aggravated despite medical treatment. Splenectomy may be an alternative option when pharmacological therapies are ineffective.

Materials and Methods

We reviewed and evaluated the cases of 3 patients with KLA who ultimately underwent splenectomy. Results: The lesions were diffusely distributed and involved the lungs and spleens of the 3 patients. Laboratory examinations revealed that all three patients had thrombocytopenia and reduced fibrinogen levels. All patients underwent symptomatic splenectomy after the medication failed. Surprisingly, their symptoms greatly improved. Histopathological investigation of the splenic lesions of the three patients confirmed the diagnosis of KLA. Immunohistochemical staining showed positivity for CD31, CD34, podoplanin, Prox-1 and angiopoietin 2 (Ang-2).

Discussion

This study aimed to review the features of KLA patients treated by splenectomy and explore the underlying link between splenectomy and prognosis. The reason for the improvement after splenectomy may be related to increased Ang-2 levels and platelet activation in patients with KLA. Future research should seek to develop more targeted drugs based on molecular findings, which may give new hope for the treatment of KLA.

Pathogenic variants in PIK3CA are associated with clinical phenotypes of kaposiform lymphangiomatosis, generalized lymphatic anomaly, and central conducting lymphatic anomaly

Complex lymphatic anomalies are debilitating conditions characterized by aberrant development of the lymphatic vasculature (lymphangiogenesis). Diagnosis is typically made by history, examination, radiology, and histologic findings. However, there is significant overlap between conditions, making accurate diagnosis difficult. Recently, genetic analysis has been offered as an additional diagnostic modality. Here, we describe four cases of complex lymphatic anomalies, all with PIK3CA variants but with varying clinical phenotypes. Identification of PIK3CA resulted in transition to a targeted inhibitor, alpelisib. These cases highlight the genetic overlap between phenotypically diverse lymphatic anomalies.

Lymphatic disorders caused by mosaic, activating KRAS variants respond to MEK inhibition

Central conducting lymphatic anomaly (CCLA) due to congenital maldevelopment of the lymphatics can result in debilitating and life-threatening disease with limited treatment options. We identified 4 individuals with CCLA, lymphedema, and microcystic lymphatic malformation due to pathogenic, mosaic variants in KRAS. To determine the functional impact of these variants and identify a targeted therapy for these individuals, we used primary human dermal lymphatic endothelial cells (HDLECs) and zebrafish larvae to model the lymphatic dysplasia. Expression of the p.Gly12Asp and p.Gly13Asp variants in HDLECs in a 2‑dimensional (2D) model and 3D organoid model led to increased ERK phosphorylation, demonstrating these variants activate the RAS/MAPK pathway. Expression of activating KRAS variants in the venous and lymphatic endothelium in zebrafish resulted in lymphatic dysplasia and edema similar to the individuals in the study. Treatment with MEK inhibition significantly reduced the phenotypes in both the organoid and the zebrafish model systems. In conclusion, we present the molecular characterization of the observed lymphatic anomalies due to pathogenic, somatic, activating KRAS variants in humans. Our preclinical studies suggest that MEK inhibition should be studied in future clinical trials for CCLA due to activating KRAS pathogenic variants.

Benign and low-grade superficial endothelial cell neoplasms in the molecular era

Vascular tumors are the most common mesenchymal neoplasms of the skin and subcutis, and they encompass a heterogeneous group with diverse clinical, histological, and molecular features, as well as biological behavior. Over the past two decades, molecular studies have enabled the identification of pathogenic recurrent genetic alterations that can be used as additional data points to support the correct classification of these lesions. The purpose of this review is to summarize the available data related to superficially located benign and low-grade vascular neoplasms and to highlight recent molecular advances with the role of surrogate immunohistochemistry to target pathogenic proteins as diagnostic biomarkers.

Kaposiform lymphangiomatosis: Diagnosis, pathogenesis, and treatment

Kaposiform lymphangiomatosis (KLA) is a life-threatening rare disease that can cause substantial morbidity, mortality, and social burdens for patients and their families. Diagnosis often occurs long after initial symptoms, and there are few centers in the world with the expertise to diagnose and care for patients with the disease. KLA is a lymphatic anomaly and significant advancements have been made in understanding its pathogenesis and etiology since its first description in 2014. This review provides multidisciplinary, comprehensive, and state-of-the-art information on KLA patient presentation, diagnostic imaging, pathology, organ involvement, genetics, and pathogenesis. Finally, we describe current therapeutic approaches, important areas for research, and challenges faced by patients and their families. Further insights into the pathogenesis of KLA may advance our understanding of other vascular anomalies given that similar signaling pathways may be involved.

The lymphatic vasculature in lung function and respiratory disease

The lymphatic vasculature maintains tissue homeostasis via fluid drainage in the form of lymph and immune surveillance due to migration of leukocytes through the lymphatics to the draining lymph nodes. Lymphatic endothelial cells (LECs) form the lymphatic vessels and lymph node sinuses and are key players in shaping immune responses and tolerance. In the healthy lung, the vast majority of lymphatic vessels are found along the bronchovascular structures, in the interlobular septa, and in the subpleural space. Previous studies in both mice and humans have shown that the lymphatics are necessary for lung function from the neonatal period through adulthood. Furthermore, changes in the lymphatic vasculature are observed in nearly all respiratory diseases in which they have been analyzed. Recent work has pointed to a causative role for lymphatic dysfunction in the initiation and progression of lung disease, indicating that these vessels may be active players in pathologic processes in the lung. However, the mechanisms by which defects in lung lymphatic function are pathogenic are understudied, leaving many unanswered questions. A more comprehensive understanding of the mechanistic role of morphological, functional, and molecular changes in the lung lymphatic endothelium in respiratory diseases is a promising area of research that is likely to lead to novel therapeutic targets. In this review, we will discuss our current knowledge of the structure and function of the lung lymphatics and the role of these vessels in lung homeostasis and respiratory disease.

Venous malformation may be a feature of EXT1-related hereditary multiple exostoses: A report of two unrelated probands

Hereditary multiple exostoses (HME), also known as hereditary multiple osteochondroma (HMO), is an autosomal dominant disorder caused by pathogenic variants in exostosin-1 or -2 (EXT1 or EXT2). It is characterized by the formation of multiple benign growing osteochondromas (exostoses) that most commonly affect the long bones; however, it may also occur throughout the body. Although many of these lesions are clinically asymptomatic, some can lead to chronic pain and skeletal deformities and interfere with adjacent neurovascular structures. Here, we report two unrelated probands that presented with a clinical and molecular diagnosis of HME with venous malformation, a clinical feature not previously reported in individuals with HME.

Case 311: Generalized Lymphatic Anomaly

HISTORY

A 14-year-old boy presented with asthenia, low back pain, and abdominal distention. The onset of symptoms was slow and progressive over a few months. The patient had no contributing past medical history. At physical examination, all vital signs were normal. Only pallor and positive fluid wave test results were noted; there was no lower limb edema, mucocutaneous lesions, or palpable lymph node enlargement. Laboratory work-up revealed a decreased hemoglobin concentration of 9.3 g/dL (normal range, 12-16 g/dL) and a decreased hematocrit level of 29.8% (normal range, 37%-45%), but all other laboratory values were normal. Contrast-enhanced CT of the chest, abdomen, and pelvis was performed.

Navigating care for rare diseases: Caregiver and patient advice for families and clinicians managing care for vascular malformations

OBJECTIVE

Families affected by rare diseases face many challenges finding adequate care and often report poor communication with clinicians. In the current study, we explore patient and caregiver advice for families and clinicians in the context of complex vascular malformations (VMs), a condition that is frequently misunderstood and misdiagnosed.

METHODS

We performed semi-structured interviews with 21 adult patients with complex VMs and 24 caregivers of children with VMs. We analyzed the transcripts using thematic analysis.

RESULTS

Participants advised patients and caregivers to advocate for care, address mental and emotional well-being, seek social support, and promote self-management and self-care. Participants advised clinicians to show care and concern, show commitment, empower and validate, communicate information clearly, address mental/emotional well-being, acknowledge the broad impact of disease and treatment, acknowledge your limitations, work as a team, and commit to learning.

CONCLUSION

Participants' advice revealed challenges related to family-centered communication and patient and caregiver quality of life and demonstrated the importance of self-advocacy and social support.

PRACTICE IMPLICATIONS

The result of this study can help newly-diagnosed families overcome challenges related to care and communication. Clinicians can also use the results to support families by offering them our accompanying handout to validate families' experiences and relay this advice.

Generalized Lymphatic Anomaly as a Differential Diagnosis of Lytic Lesions

Generalized lymphatic anomaly (GLA) is an infrequent multiorgan disease characterized by the presence of abnormal proliferation of lymphatic vessels. The diagnosis requires histological confirmation, and the treatment is controversial. We are presenting a case of a 28-year-old male patient who was diagnosed with an extragonadal mediastinal nonseminomatous germ cell tumor. He underwent chemotherapy, and during this treatment, radiologic findings evidenced lytic lesions. Multiple biopsies were performed, which revealed the presence of abnormal lymphatic vessels, characteristic of GLA. There are different etiologies of osteolytic lesions, and on some occasions, they mimic a tumoral entity. The clinical suspicion of GLA is the first step in approaching the diagnosis, particularly in young adult patients.

Case report: Multiple brain intravascular papillary endothelial hyperplasia: incidence, diagnostic challenges, and management approach

Multiple hemorrhagic brain lesions are mainly diagnosed based on clinico-radiological features integrated with histological data. Intravascular papillary endothelial hyperplasia (IPEH), or Masson's tumor, is a very rare entity, particularly when localized in the brain. In this study, we describe a case of multiple recurrent brain IPEHs and provide details on the diagnostic phase, therapeutic approaches, and related challenges. A 55-year-old woman presented with a relapsing neurological deficit. Brain magnetic resonance imaging (MRI) revealed a hemorrhagic right frontal-parietal lesion. When new neurological symptoms occurred, subsequent MRI scans detected more bleeding cerebral lesions. She underwent a series of single hemorrhagic lesion debulking. For any samples that underwent histopathological examination, the first results were not informative; the second and the third results revealed hemangioendothelioma (HE); and the fourth results led to the IPEH diagnosis. Interferon alpha (IFN-α) and subsequently sirolimus were prescribed. Both were well tolerated. Clinical and radiological features remained stable 43 months after starting sirolimus therapy and 132 months after the first diagnosis. To date, 45 cases of intracranial IPEH have been reported, mostly as single lesions without parenchymal location. They are usually treated by surgery and sometimes by radiotherapy upon recurrence. Our case is notable for two main reasons: because of the consecutive recurrent multifocal exclusively cerebral lesions and the therapeutic approach we used. Based on multifocal brain recurrence and good performance, we propose pharmacological therapy, including IFN-α and sirolimus, to stabilize IPEH.

Anemia in the pediatric patient

The World Health Organization estimates that approximately a quarter of the world's population suffers from anemia, including almost half of preschool-age children. Globally, iron deficiency anemia is the most common cause of anemia. Other important causes of anemia in children are hemoglobinopathies, infection, and other chronic diseases. Anemia is associated with increased morbidity, including neurologic complications, increased risk of low birth weight, infection, and heart failure, as well as increased mortality. When approaching a child with anemia, detailed historical information, particularly diet, environmental exposures, and family history, often yield important clues to the diagnosis. Dysmorphic features on physical examination may indicate syndromic causes of anemia. Diagnostic testing involves a stepwise approach utilizing various laboratory techniques. The increasing availability of genetic testing is providing new mechanistic insights into inherited anemias and allowing diagnosis in many previously undiagnosed cases. Population-based approaches are being taken to address nutritional anemias. Novel pharmacologic agents and advances in gene therapy-based therapeutics have the potential to ameliorate anemia-associated disease and provide treatment strategies even in the most difficult and complex cases.

How we approach the use of sirolimus and new agents: Medical therapy to treat vascular anomalies

Vascular anomalies (VAs) are a heterogeneous group of primarily congenital tumors and malformations. The International Society for the Study of Vascular Anomalies (ISSVA) has developed a standard classification of these disorders, creating a uniform approach to their diagnosis. Recent discoveries evaluating the genetic causes of VAs have revealed that they are due to mutations in cancer pathways, including the PI3K/AKT/mTOR and RAS/MAPK/MEK pathways. These discoveries have led to improved phenotype-genotype correlation and have expanded medical therapy for this group of unique disorders.

How we approach the diagnosis and management of complex lymphatic anomalies

Complex lymphatic anomalies (CLA) are congenital diseases of the lymphatic circulation system that are associated with significant morbidity and early mortality. While guidelines for the comprehensive evaluation of the CLA were recently published, the diagnostic approach and medical management are not standardized. This article presents the clinical features of four CLA: Gorham-Stout disease, generalized lymphatic anomaly, kaposiform lymphangiomatosis, and central collecting lymphatic anomaly. We also offer three cases from the authors' practice and our views on diagnostic testing and disease management including supportive care, medical therapies, and other interventions.

How we approach the diagnosis of a vascular anomaly

Vascular anomalies represent a diverse group of complex disorders that can cause significant complications, including coagulopathies, pain, and decreased function. The diagnosis of vascular anomalies is often challenging due to heterogeneity of presenting phenotypes and overlapping clinical features with other pediatric conditions. Pediatric hematologists/oncologists (PHO) are uniquely positioned for an essential role in diagnosing, managing, and coordinating the multidisciplinary care required to maximize the quality of life of these patients. Here, we review the diagnostic approach involved in patients with vascular anomalies and utilize cases to highlight the challenges involved, and how PHOs can play a vital part in the care of these patients.

Kaposiform Lymphangiomatosis: Pathologic Aspects in 43 Patients

Kaposiform lymphangiomatosis is an uncommon generalized lymphatic anomaly with distinctive clinical, radiologic, histopathologic, and molecular findings. Herein, we document the pathology in 43 patients evaluated by the Boston Children's Hospital Vascular Anomalies Center from 1999 to 2020. The most frequent presentations were respiratory difficulty, hemostatic abnormalities, and a soft tissue mass. Imaging commonly revealed involvement of some combination of mediastinal, pulmonary, pleural, and pericardial compartments and most often included spleen and skeleton. Histopathology was characterized by dilated, redundant, and abnormally configured lymphatic channels typically accompanied by dispersed clusters of variably canalized, and often hemosiderotic, spindled lymphatic endothelial cells that were immunopositive for D2-40, PROX1, and CD31. An activating lesional NRAS variant was documented in 9 of 10 patients. The clinical course was typically aggressive, marked by hemorrhage, thrombocytopenia, diminished fibrinogen levels, and a mortality rate of 21%.

Mapping the PIK3CA-related overgrowth spectrum (PROS) patient and caregiver journey using a patient-centered approach

BACKGROUND

PROS disorders are driven by somatic, gain-of-function mutations in PIK3CA that result in hyperactivation of the phosphatidylinositol-3-kinase (PI3K) signaling pathway. PROS encompasses a broad spectrum of overlapping phenotypes (including overgrowth and vascular malformations) that vary significantly in their severity; every case is unique, leading to different, complex experiences. Here, we aim to describe the PROS experience from the patients' and caregivers' points of view, from onset to diagnosis to treatment and support.

RESULTS

The PROS patient journey was developed using a literature review, an ethnography study, health care professional (HCP) research, and social listening. It was then validated with patients, caregivers, and patient advocates. Physician research included 94 PROS centers and other vascular anomaly centers throughout the United States and Europe. Ethnographic research included 24 patients, caregivers, and/or advocates; selected data from 223 patients were reviewed. Key priority areas of need were identified, along with barriers to and potential enablers of quality care. Visual mapping of the PROS patient and family journey was developed to identify key personal health and system issues, and opportunities for improvements throughout patients' lifespans. Maps were also developed for 3 specific conditions: Klippel-Trénaunay syndrome (K-T); congenital lipomatous overgrowth, vascular malformations, epidermal nevi, scoliosis/skeletal and spinal anomalies (CLOVES) syndrome; and megalencephaly-capillary malformation syndrome (M-CM). Overall, most patients with PROS conditions and their families struggle with a long path to diagnosis, access to genetic testing, and finding qualified specialists. Following diagnosis, patients and families are frequently challenged with major medical events, comorbidities, unpredictability, frequent hospitalization, impact on school and work, the need for multidisciplinary care, unwanted attention, adverse impact on mental and emotional health, and financial pressures. Lack of effective pain management emerged as a substantial issue. Challenges and barriers to quality care shift throughout patients' lifespans; transition from pediatric to adult care can be especially difficult.

CONCLUSIONS

This patient journey in PROS was created in collaboration with patients, caregivers, and advocates as key partners. This novel methodology, which could be applied elsewhere, can more accurately identify areas of unmet need, barriers to care, education topics, and assist HCPs to understand the patient and family perspective.

A precision medicine approach to hereditary hemorrhagic telangiectasia and complex vascular anomalies

Vascular anomalies represent a diverse group of disorders classified broadly as malformations or tumors and include the second most common hereditary bleeding disorder worldwide, hereditary hemorrhagic telangiectasia (HHT). Patients with HHT and other vascular anomalies suffer morbid consequences of these diseases, including bleeding, thrombosis, anemia, localized intravascular coagulation, tissue overgrowth, infections, and other complications. The International Society for the Study of Vascular Anomalies (ISSVA) has developed a standard classification of these disorders, creating a uniform approach to their diagnosis, and the treatments for vascular anomalies are rapidly evolving. Recent discoveries have elucidated the molecular basis of a number of common and uncommon vascular anomalies. HHT occurs due to mutations in the transforming growth factor beta (TGF-β) pathway, resulting in vascular endothelial growth factor excess. Complex vascular anomalies including Klippel-Trénaunay syndrome (KTS) and arteriovenous malformation (AVM) may occur due to mutations in the PI3K/AKT/mTOR and RAS/MAPK/MEK pathways. The discovery of the pathophysiologic mechanisms driving these diseases has led to improved phenotype-genotype correlation and the opportunity to target molecular pathways with medical therapies. Therefore, targeted agents have quickly become a standard of care in the treatment of vascular disorders (particularly HHT). Herein, we provide a case-based approach to the use of antiangiogenic therapies including bevacizumab and pazopanib for the treatment of bleeding in HHT and the use of mammalian target of rapamycin (sirolimus), PIK3CA (alpelisib), and MEK (trametinib) inhibitors in the treatment of complex vascular anomalies.

Keratosis pilaris rubra successfully treated with topical sirolimus: Report of a case and review of the literature

Keratosis pilaris rubra (KPR) is a subtype of keratosis pilaris (KP) presenting with numerous "grainlike" follicular papules in a background of confluent erythema most often affecting the face and upper extremities with persistence beyond puberty. Treatment has remained challenging with inconsistent benefit from topical therapies such as emollients, keratolytics, corticosteroids, and retinoids, though case reports documenting success with pulsed dye laser therapy have been found. We present a case of KPR in a 15-year-old boy who was successfully treated with topical sirolimus 1% cream.

Sirolimus used for treatment of retroperitoneal arteriovenous malformation in a premature neonate

We describe a case of a premature infant with antenatally detected retroperitoneal arteriovenous malformation (AVM) with extensive intraspinal extension. Treatment of the malformation with embolectomy and sclerotherapy was not feasible in view of intraspinal extensions and small size of vessels of the lesion. During a trial of propranolol over 20 days, the lesion progressed in size, roughly doubling in volume and was accompanied with deranged coagulation parameters. Treatment was therefore switched to oral prednisolone and sirolimus. The steroid was stopped after 6 weeks and sirolimus was continued with serum drug level monitoring and serial imaging of the malformation. After 4 months of sirolimus, the AVM remained at the same size as at the start of treatment, thus we propose that the drug may have arrested the growth of the lesion. This case highlights the use of sirolimus in management of AVMs in infants.

Kaposiform lymphangiomatosis presenting with a Group A Streptococcus pericardial effusion

A 4-year-old child was transferred to the paediatric intensive care unit with acute respiratory failure following 4 days of fever, nausea and vomiting. Chest X-ray on admission had an enlarged cardiac silhouette and transthoracic echo confirmed a large pericardial effusion. An emergent pericardiocentesis was performed at bedside which drained nearly 1000 mL of purulent fluid. Postdrainage course was complicated by acute systolic and diastolic heart failure, thrombocytopenia and acute renal failure. A chest CT and MRI were concerning for a diffuse mediastinal soft-tissue density, so the patient underwent interventional radiology-guided biopsy complicated by haemorrhage requiring mediastinal exploration and subtotal thymectomy. Histopathology revealed changes consistent with kaposiform lymphangiomatosis and MRI demonstrated involvement of the lumbar spine and right hip. Following a course of intravenous antibiotics, the patient was started on sirolimus and prednisolone and ultimately discharged home.

Systemic, local, and sclerotherapy drugs: What do we know about drug prescribing in vascular anomalies?

Off-label drug prescribing, frequent in the treatment of vascular anomalies (VA), relies on the quality of the literature reporting drug efficacy and safety. Our objective is to review the level of evidence (LOE) surrounding drug use in VA, which is more prevalent in pediatric care. A list of drugs used in VA was created with a literature review in July 2020. For each drug listed, the article displaying the highest LOE was determined and then compared between efficacy/safety data, routes of administration, pharmacological categories and a subset of VA. The influence of research quality on study results was also explored. The median LOE for the 74 drugs identified poor methodological quality, with a predominance of retrospective studies or case reports. Drug safety is currently inadequately reported. This is alarming as many treatments display significant safety concerns. Also, current literature displays major publication bias that probably leads to overestimation of drug efficacy in VA.

Lymphatic Malformation Responsive to Sirolimus in Keratinocytic Epidermal Nevus Syndrome with KRAS Mutation: A Case and Brief Literature Discussion

We present a rare case of KRAS keratinocytic epidermal nevus syndrome with lymphatic malformation, responsive to treatment with sirolimus, an mTOR inhibitor. A brief review of the current literature regarding sirolimus use in vascular malformations, lymphatic malformations, regional overgrowth syndromes, and RASopathies is discussed.

Development and physiological functions of the lymphatic system: insights from human genetic studies of primary lymphedema

Primary lymphedema is a long-term (chronic) condition characterized by tissue lymph retention and swelling that can affect any part of the body, although it usually develops in the arms or legs. Due to the relevant contribution of the lymphatic system to human physiology, while this review mainly focuses on the clinical and physiological aspects related to the regulation of fluid homeostasis and edema, clinicians need to know that the impact of lymphatic dysfunction with a genetic origin can be wide ranging. Lymphatic dysfunction can affect immune function so leading to infection; it can influence cancer development and spread, and it can determine fat transport so impacting on nutrition and obesity. Genetic studies and the development of imaging techniques for the assessment of lymphatic function have enabled the recognition of primary lymphedema as a heterogenic condition in terms of genetic causes and disease mechanisms. In this review, the known biological functions of several genes crucial to the development and function of the lymphatic system are used as a basis for understanding normal lymphatic biology. The disease conditions originating from mutations in these genes are discussed together with a detailed clinical description of the phenotype and the up-to-date knowledge in terms of disease mechanisms acquired from in vitro and in vivo research models.

Newcomers in Vascular Anomalies

Vascular anomalies are composed of tumors and malformations and with overlapping histologies, thus are often misdiagnosed or labeled with imprecise terminology. Lesions are common and usually diagnosed during infancy or childhood; the estimated prevalence is 4.5%. Vascular tumors rapidly enlarge postnatally and demonstrate endothelial proliferation. Malformations are errors in vascular development with stable endothelial turnover; they are typically named based on the primary vessel that is malformed (capillary, arterial, venous, lymphatic). This article reviews the pathologic and molecular genetic characteristics for select recently described vascular anomalies.

Generalized lymphatic anomalies and review of the current management landscape: a case report and review of the literature

BACKGROUND

Generalized lymphatic anomaly previously known as diffuse systemic lymphangiomatosis is a rare multisystem congenital disease arising from the lymphatic system, and it is characterized by abnormal proliferation of the lymphatic channels in osseous and extraosseous tissues. It typically affects children or young adults. Although it is benign, it can be misdiagnosed as malignancy because of its diffuse and debilitating nature depending on the site of involvement. Due to its rarity, diagnosis is often delayed, leading to potential significant morbidity or mortality if vital organs are involved. Furthermore, its potential for multiorgan involvement with no curative treatment makes its management challenging.

CASE PRESENTATION

We describe a case of a 35-year-old Caucasian female, who presented with epigastric pain and was subsequently extensively investigated at multiple tertiary centers by numerous specialists for query malignancy and metabolic bone disorder following incidental computed tomography imaging findings of multiple osteolytic lesions in the axial skeleton, and low-attenuating lesions in the axilla, spleen, and mediastinum. The diagnosis was confirmed with an axillary excisional biopsy. She was clinically stable with no end organ damage. She was monitored conservatively.

CONCLUSIONS

The case illustrates the importance of increased awareness among clinicians for this rare congenital disease to enable earlier diagnosis and to avoid unnecessary invasive investigations. Furthermore, this case highlights the potential need for multiple biopsies of affected sites to confirm diagnosis. We also discuss the emergence of interferon therapy, chemotherapy, immunosuppression, and immunotherapy as medical management for this condition.

A review of mechanisms of disease across PIK3CA-related disorders with vascular manifestations

BACKGROUND

PIK3CA-related disorders include vascular malformations and overgrowth of various tissues that are caused by postzygotic, somatic variants in the gene encoding phosphatidylinositol-3-kinase (PI3K) catalytic subunit alpha. These mutations result in activation of the PI3K/AKT/mTOR signaling pathway. The goals of this review are to provide education on the underlying mechanism of disease for this group of rare conditions and to summarize recent advancements in the understanding of, as well as current and emerging treatment options for PIK3CA-related disorders.

MAIN BODY

PIK3CA-related disorders include PIK3CA-related overgrowth spectrum (PROS), PIK3CA-related vascular malformations, and PIK3CA-related nonvascular lesions. Somatic activating mutations (predominantly in hotspots in the helical and kinase domains of PIK3CA, but also in other domains), lead to hyperactivation of the PI3K signaling pathway, which results in abnormal tissue growth. Diagnosis is complicated by the variability and overlap in phenotypes associated with PIK3CA-related disorders and should be performed by clinicians with the required expertise along with coordinated care from a multidisciplinary team. Although tissue mosaicism presents challenges for confirmation of PIK3CA mutations, next-generation sequencing and tissue selection have improved detection. Clinical improvement, radiological response, and patient-reported outcomes are typically used to assess treatment response in clinical studies of patients with PIK3CA-related disorders, but objective assessment of treatment response is difficult using imaging (due to the heterogeneous nature of these disorders, superimposed upon patient growth and development). Despite their limitations, patient-reported outcome tools may be best suited to gauge patient improvement. New therapeutic options are needed to provide an alternative or supplement to standard approaches such as surgery and sclerotherapy. Currently, there are no systemic agents that have regulatory approval for these disorders, but the mTOR inhibitor sirolimus has been used for several years in clinical trials and off label to address symptoms. There are also other agents under investigation for PIK3CA-related disorders that act as inhibitors to target different components of the PI3K signaling pathway including AKT (miransertib) and PI3K alpha (alpelisib).

CONCLUSION

Management of patients with PIK3CA-related disorders requires a multidisciplinary approach. Further results from ongoing clinical studies of agents targeting the PI3K pathway are highly anticipated.