BRAF and RAS Mutations in Sporadic and Secondary Pyogenic Granuloma

Spontaneous multifocal pyogenic granulomas

Cutaneous pyogenic granulomas (PGs) are common, benign vascular tumors of uncertain pathogenesis; however, a growing body of literature suggests that the formation of PGs may be secondary to genetic alterations in both the Ras/Raf/MAPK and PI3K/Akt/mTOR pathways. We present three cases of spontaneous multifocal PGs that first presented in infancy, were not associated with other vascular anomalies or discernable etiology, harbored somatic genetic variants in the Ras/Raf/MAPK pathway (NRAS n = 2, FGFR1 n = 1), were refractory to treatment with beta-blockers and mTOR inhibitors, and responded best to pulsed dye laser. We propose the term "spontaneous multifocal PGs" to describe this entity.

Congenital Vascular and Lymphatic Diseases

Over the past several centuries, the integration of contemporary medical techniques and innovative technologies, like genetic sequencing, have played a pivotal role in enhancing our comprehension of congenital vascular and lymphatic disorders. Nonetheless, the uncommon and complex characteristics of these disorders, especially considering their formation during the intrauterine stage, present significant obstacles in diagnosis and treatment. Here, we review the intricacies of these congenital abnormalities, offering an in-depth examination of key diagnostic approaches, genetic factors, and therapeutic methods.

Capillary Hemangioma of the Spinal Cord: Case Report and Systematic Review of Literature

BACKGROUND

Capillary hemangiomas are rare vascular lesions that rarely affect the central nervous system. When they present within the spinal canal, they are typically confined intradurally, with intramedullary extension rare. We present a rare case of spinal intramedullary capillary hemangioma, with a systematic review of the literature.

METHODS

Medical records and imaging data were retrospectively reviewed using the health record software EPIC (Verona, Wisconsin, USA) and the radiology management software system RIS/PACS (Radiology Information System/Picture Archiving and Communication System; QREADS). The report was written in accordance with the CARE (case reports) guidelines. We also performed a systematic review of the literature on all cases of intramedullary spinal capillary hemangiomas in accordance with PRISMA (preferred reporting items for systematic reviews and meta-analyses) guidelines.

RESULTS

We report a case of a 54-year-old man who presented with progressive paraplegia and sensory deficits in the lower extremities. Spinal magnetic resonance imaging showed an intramedullary enhancing lesion centered at T11 with associated spinal cord compression. He underwent thoracic laminectomy and gross total resection of the lesion without complications and subsequent improvement on his neurological examination. Histological examination showed findings consistent with a capillary hemangioma. The literature review also documented 21 studies with a combined total of 38 cases of intramedullary spinal capillary hemangioma.

CONCLUSIONS

Purely intramedullary capillary hemangiomas are unusual spinal lesions with only a few cases reported in the literature. These should be considered in the differential diagnosis of intramedullary tumors. Surgical management remains the first line of treatment for symptomatic patients.

Extracranial Vascular Anomalies Driven by RAS/MAPK Variants: Spectrum and Genotype-Phenotype Correlations

BACKGROUND

We aimed to correlate alterations in the rat sarcoma virus (RAS)/mitogen-activated protein kinase pathway in vascular anomalies to the clinical phenotype for improved patient and treatment stratification.

METHODS AND RESULTS

This retrospective multicenter cohort study included 29 patients with extracranial vascular anomalies containing mosaic pathogenic variants (PVs) in genes of the RAS/mitogen-activated protein kinase pathway. Tissue samples were collected during invasive treatment or clinically indicated biopsies. PVs were detected by the targeted sequencing of panels of genes known to be associated with vascular anomalies, performed using DNA from affected tissue. Subgroup analyses were performed according to the affected genes with regard to phenotypic characteristics in a descriptive manner. Twenty-five vascular malformations, 3 vascular tumors, and 1 patient with both a vascular malformation and vascular tumor presented the following distribution of PVs in genes: Kirsten rat sarcoma viral oncogene (n=10), neuroblastoma ras viral oncogene homolog (n=1), Harvey rat sarcoma viral oncogene homolog (n=5), V-Raf murine sarcoma viral oncogene homolog B (n=8), and mitogen-activated protein kinase kinase 1 (n=5). Patients with RAS PVs had advanced disease stages according to the Schobinger classification (stage 3-4: RAS, 9/13 versus non-RAS, 3/11) and more frequent progression after treatment (RAS, 10/13 versus non-RAS, 2/11). Lesions with Kirsten rat sarcoma viral oncogene PVs infiltrated more tissue layers compared with the other PVs including other RAS PVs (multiple tissue layers: Kirsten rat sarcoma viral oncogene, 8/10 versus other PVs, 6/19).

CONCLUSIONS

This comparison of patients with various PVs in genes of the RAS/MAPK pathway provides potential associations with certain morphological and clinical phenotypes. RAS variants were associated with more aggressive phenotypes, generating preliminary data and hypothesis for future larger studies.

Updates in Genetic Testing for Head and Neck Vascular Anomalies

Vascular anomalies include benign or malignant tumors or benign malformations of the arteries, veins, capillaries, or lymphatic vasculature. The genetic etiology of the lesion is essential to define the lesion and can help navigate choice of therapy. . In the United States, about 1.2% of the population has a vascular anomaly, which may be underestimating the true prevalence as genetic testing for these conditions continues to evolve.

Oral Pyogenic Granuloma: A Narrative Review

Pyogenic granuloma (PG) is a benign vascular lesion found predominantly in the oral cavity. Characterized by rapid growth and propensity to bleed, PG presents diagnostic challenges due to its similarity and alarming proliferation. This narrative review synthesizes current knowledge on the epidemiology, etiopathogenesis, clinical manifestations, and management of oral PG, with emphasis on recent advances in diagnostic and therapeutic approaches. The epidemiology of the injury is meticulously analyzed, revealing a higher incidence in women and a wide range of ages of onset. It delves into the etiopathogenesis, highlighting the uncertainty surrounding the exact causal factors, although historical attributions suggest an infectious origin. It exhaustively analyzes the clinical and histopathological aspects of oral PG, offering information on its various presentations and the importance of an accurate diagnosis to guide effective treatment. It details treatment strategies, emphasizing the personalized approach based on individual patient characteristics. This comprehensive review consolidates current knowledge on oral PG, highlighting the need for further research to clarify its pathogenesis and optimize treatment protocols.

A case report and literature review on reactive cutaneous capillary endothelial proliferation induced by camrelizumab in a nasopharyngeal carcinoma patient

Camrelizumab, a monoclonal antibody, blocks programmed cell death protein-1 from binding to T cells and programmed cell death ligand 1 on tumor cells, thereby ensuring sustained T cell activation and blocking immune escape of various types of cancer, including nasopharyngeal carcinoma. Reactive cutaneous capillary endothelial hyperplasia (RCCEP) is the most common immune-related adverse event in patients treated with camrelizumab. We report a case nasopharyngeal carcinoma in a patient with camrelizumab-induced RCCEP. A 68-year-old man diagnosed with nasopharyngeal carcinoma developed RCCEP at multiple locations after 3 months of camrelizumab treatment. RCCEP of the right lower eyelid affected closure of the right eye. In this report, we also reviewed previous literature on camrelizumab-induced RCCEP. In summary, the mechanism underlying camrelizumab-induced RCCEP remains unclear. RCCEP typically gradually subsides after discontinuing camrelizumab treatment. Larger nodules can be treated with lasers, ligation, or surgery. Although surgical excision is effective, RCCEP may recur in patients undergoing camrelizumab treatment. RCCEP management may not be required in the absence of adverse effects on the patient's daily life.

Lobular capillary hemangioma (pyogenic granuloma) of the gastrointestinal tract: Clinicopathologic analysis of 34 cases

OBJECTIVES

Lobular capillary hemangioma (LCH) rarely involves the gastrointestinal (GI) tract. This study describes clinicopathologic features of LCH in a cohort of GI cases.

METHODS

We defined lobular capillary hemangioma as "a proliferation of capillary-sized blood vessels arranged at least focally in a lobular configuration," searched departmental archives for cases, and recorded clinicopathologic findings.

RESULTS

We identified 34 GI tract LCHs from 16 men and 10 women; 4 patients had multiple lesions. Mean age was 64 years. Cases arose in the esophagus (n = 7), stomach (n = 3), small bowel (n = 7), and colorectum (n = 17). Twelve patients had anemia or rectal bleeding. No patients had a known genetic syndrome. The lesions manifested as mucosal polyps, with median size of 1.3 cm. Microscopically, 20 lesions were ulcerated, and most involved the mucosa, with 9 extending into the submucosa. Vessel dilation was present in 27 patients, endothelial hobnailing in 13, hemorrhage in 13, and focal reactive stromal atypia in 2. Follow-up information was available for 10 patients, none of whom developed same-site recurrence. Six of the 26 cases (23%) were extradepartmental consultations, including 2 of the multifocal cases.

CONCLUSIONS

Gastrointestinal tract LCHs often arise as colorectal polyps. They are typically small but can reach a few centimeters in size and can be multifocal.

The Genetic Architecture of Vascular Anomalies: Current Data and Future Therapeutic Perspectives Correlated with Molecular Mechanisms

Vascular anomalies (VAs) are morphogenesis defects of the vascular system (arteries, capillaries, veins, lymphatic vessels) singularly or in complex combinations, sometimes with a severe impact on the quality of life. The progress made in recent years with the identification of the key molecular pathways (PI3K/AKT/mTOR and RAS/BRAF/MAPK/ERK) and the gene mutations that lead to the appearance of VAs has allowed the deciphering of their complex genetic architecture. Understanding these mechanisms is critical both for the correct definition of the phenotype and classification of VAs, as well as for the initiation of an optimal therapy and the development of new targeted therapies. The purpose of this review is to present in synthesis the current data related to the genetic factors involved in the etiology of VAs, as well as the possible directions for future research. We analyzed the data from the literature related to VAs, using databases (Google Scholar, PubMed, MEDLINE, OMIM, MedGen, Orphanet) and ClinicalTrials.gov. The obtained results revealed that the phenotypic variability of VAs is correlated with genetic heterogeneity. The identification of new genetic factors and the molecular mechanisms in which they intervene, will allow the development of modern therapies that act targeted as a personalized therapy. We emphasize the importance of the geneticist in the diagnosis and treatment of VAs, as part of a multidisciplinary team involved in the management of VAs.

23-Year-old male with multiple giant facial pyogenic granulomas being treated with combined topical timolol and steroid: A case report

Introduction and importance

Pyogenic Granuloma (PG) commonly presents as a solitary, erythematous, non-tender, skin lesion, usually not exceeding 2.5 cm. Although Surgical excision is the first-line treatment, conservative treatments are recently developing. Solitary PG is well documented unlike multiple PGs, as the latter is rarely described in terms of its presentations and treatments.

Case presentation

This interesting case report describes a 23-year-old male who developed multiple PGs on the nasal area (2cmx2cm) and mandibular area (10cmx2cm) after sutures removal secondary to a recent history of trauma. The lesions regressed after successfully treated with two months of timolol drops and topical corticosteroids. Subsequently, intralesional corticosteroids injections were given once-per-month for two months, with residual fibrosis of the regressed lesion.

Clinical discussion

While the most common site for multiple PGs is the interscapular region, this case reports giant, facial, multiple PGs followed suture removal. Although β-blockers were reported to successfully treat solitary PG, only a few cases were raised to discuss this treatment in terms of multiple PGs. This case completes the series and reports successfully-treated multiple PGs using a combination of topical timolol and steroid.

Conclusion

This case supports the need to consider multiple PGs as a differential diagnosis following sutures removal even when it reaches rarely reported diameters. Also, it suggests topical timolol and steroids as an effective conservative treatment in similar cases of multiple giant PGs. Notably, the treatment failed to sidestep scar formation.

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This report acts as a proof of the efficacy of topical timolol and steroid as a conservative treatment for multiple Pyogenic Granulomas, even when the lesions reach a large diameter.

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It is noteworthy that this treatment failed to sidestep scar formation.

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This case supports the need to consider Pyogenic Granulomas a differential diagnosis after sutures removal.

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This case highlights the fact that multiple Pyogenic Granulomas can reach diameters larger than 2 cm.

How we approach hemangiomas in infants

Pediatric oncologists are increasingly involved in the management of benign vascular tumors and their associated life-threatening complications. Hemangiomas are the most common referring diagnosis to multidisciplinary vascular anomalies clinics. However, as contemporary research has revealed, hemangiomas are not a single, easily defined entity but rather a diverse set of related vascular tumors, each having a unique natural history, growth pattern, and response to therapy. This manuscript seeks to illustrate how we evaluate and manage these complex tumors, their complications, and associated syndromes, while remaining ever vigilant for malignant hemangioma mimickers such as soft tissue sarcomas and congenital leukemia.

How we approach genetics in the diagnosis and management of vascular anomalies

Vascular anomalies are a heterogeneous group of disorders that are currently classified based on their clinical and histological characteristics. Over the past decade, there have been significant advances in molecular genetics that have led to identification of genetic alterations associated with vascular tumors, vascular malformations, and syndromes. Here, we describe known genetic alterations in vascular anomalies, discuss when and how to test, and examine how identification of causative genetic mutations provides for better management of these disorders through improved understanding of their pathogenesis and increasing use of targeted therapeutic agents in order to achieve better outcomes for our patients.

Molecular Pathways and Possible Therapies for Head and Neck Vascular Anomalies

Vascular Anomalies are a heterogenous group of vascular lesions that can be divided, according to the International Society for the Study of Vascular Anomalies Classification, into two main groups : Vascular Tumors and Vascular Malformations. Vascular Malformations can be further subdivided into slow-flow and fast-flow malformations. This clinical and radiological classification allows for a better understanding of vascular anomalies and aims to offer a more precise final diagnosis. Correct diagnosis is essential to propose the best treatment, which traditionally consists of surgery, embolization or sclerotherapy. Since a few years, medical treatment has become an important part of multidisciplinary treatment. Genetic and molecular knowledge of vascular anomalies are increasing rapidly and opens the door for a molecular classification of vascular anomalies according to the underlying pathways involved. The main pathways seem to be: PI3K/AKT/mTOR (PIKopathies) and RAS/RAF/MEK/ERK (RASopathies). Knowing the underlying molecular cascades allows us to use targeted medical therapies. The first part of this article aims to review the vascular anomalies seen in the head and neck region and their underlying molecular causes and involved pathways. The second part will propose an overview of the available targeted therapies based on the affected molecular cascade. This article summarizes theragnostic treatments available in vascular anomalies.

Recurrent Alterations in the MAPK pathway in Sporadic Pyogenic Granuloma of Childhood

Pyogenic granuloma is one of the most common vascular tumours. The cause of pyogenic granuloma was previously thought to be an inflammatory reaction with consecutive stimulation of endothelial cell proliferation. However, recent studies suggest that pyogenic granuloma may be driven by constitutive activation of the mitogen-activated protein kinase pathway. The aim of this study was to investigate the molecular profile of sporadic pyogenic granuloma of childhood, using a systematic approach scrutinizing potential aberrations within different oncogenic pathways. Within a retrospective setting pyogenic granuloma of 15 patients was analysed by targeted next generation sequencing using the Oncomine Focus Assay, which includes genes of key tumorigenic signalling pathways. Activating mutations were found in 4 out of 15 cases (27%). Two HRAS hotspot mutations (p.Gly13Arg, p.Ala59Thr), 1 BRAF (p.Val600Glu) mutation and a novel, previously not reported, MAP2K1 hotspot mutation (p.Glu203Lys) were identified. It is notable that all of these genes are involved in constitutive mitogen- activated protein kinase signalling. This study increases the range of underlying genetic alterations in pyogenic granuloma by identifying novel oncogenic mutations in crucial mitogen-activated protein kinase pathway genes. The results provide supporting evidence that activated mitogen-activated protein kinase signalling is a key driver in the pathogenesis of pyogenic granuloma, which might be exploited by targeted treatment approaches for selected cases.

NRASQ61R mutation in human endothelial cells causes vascular malformations

Somatic mutations in NRAS drive the pathogenesis of melanoma and other cancers but their role in vascular anomalies and specifically human endothelial cells is unclear. The goals of this study were to determine whether the somatic-activating NRAS^Q61R mutation in human endothelial cells induces abnormal angiogenesis and to develop in vitro and in vivo models to identify disease-causing pathways and test inhibitors. Here, we used mutant NRAS^Q61R and wild-type NRAS (NRAS^WT) expressing human endothelial cells in in vitro and in vivo angiogenesis models. These studies demonstrated that expression of NRAS^Q61R in human endothelial cells caused a shift to an abnormal spindle-shaped morphology, increased proliferation, and migration. NRAS^Q61R endothelial cells had increased phosphorylation of ERK compared to NRAS^WT cells indicating hyperactivation of MAPK/ERK pathways. NRAS^Q61R mutant endothelial cells generated abnormal enlarged vascular channels in a 3D fibrin gel model and in vivo, in xenografts in nude mice. These studies demonstrate that NRAS^Q61R can drive abnormal angiogenesis in human endothelial cells. Treatment with MAP kinase inhibitor U0126 prevented the change to a spindle-shaped morphology in NRAS^Q61R endothelial cells, whereas mTOR inhibitor rapamycin did not.

Recurrent driver mutations in benign tumors

The understanding of the molecular pathogenesis of benign tumors may bring essential information to clarify the process of tumorigenesis, and ultimately improve the understanding of events such as malignant transformation. The definition of benign neoplasia is not always straightforward and herein the issues surrounding this concept are discussed. Benign neoplasms share all cancer hallmarks with malignancies, except for metastatic potential. Recently, next-generation sequencing has provided unprecedented opportunities to unravel the genetic basis of benign neoplasms and, so far, we have learned that benign neoplasms are indeed characterized by the presence of genetic mutations, including genes rearrangements. Driver mutations in advanced cancer are those that confer growth advantage, and which have been positively selected during cancer evolution. Herein, some discussion will be brought about this concept in the context of cancer prevention, involving precursor lesions and benign neoplasms. When considering early detection and cancer prevention, a driver mutation should not only be advantageous (i.e., confer survival advantage), but predisposing (i.e., promoting a cancer phenotype). By including the benign counterparts of malignant neoplasms in tumor biology studies, it is possible to evaluate the risk posed by a given mutation and to differentiate advantageous from predisposing mutations, further refining the concept of driver mutations. Therefore, the study of benign neoplasms should be encouraged because it provides valuable information on tumorigenesis central for understanding the progression from initiation to malignant transformation.

Segmental undergrowth is associated with pathogenic variants in vascular malformation genes: A retrospective case-series study

Segmental overgrowth has been widely described in patients with congenital vascular anomalies. However, segmental undergrowth has been poorly characterized, and no large series of patients have been published. We present the clinical and molecular characteristics a cohort of 37 patients with vascular malformations and segmental undergrowth. True undergrowth was only considered when the musculoskeletal system was involved to avoid confusion with other causes of segmental reduction, as in lipodystrophy or the long-term osteopenia seen in patients with Servelle-Martorell syndrome. Deep high-throughput sequencing was performed in tissue samples from 20 patients using a custom panel. We identified three groups: undergrowth associated with (1) venous, (2) capillary-venous, and (3) lymphatic-capillary-venous malformations. Congenital or early childhood onset undergrowth can occur with or without associated overgrowth. Different likely pathogenic or pathogenic variants were detected in 13 of 20 (65%) tissue samples in the PIK3CA, TEK, GNAQ, or GNA11 genes. In conclusion, the eponymous Servelle-Martorell syndrome should not be used as a synonym for undergrowth. Segmental undergrowth should be considered a characteristic associated with vascular malformations. Patients with PIK3CA variants show all different combinations of overgrowth and undergrowth. Thus, the term PROS (PIK3CA-related overgrowth spectrum) does not cover the entire spectrum.

Cutaneous epithelioid hemangiomas show somatic mutations in the MAPK pathway

BACKGROUND

Epithelioid hemangioma (EH) arising from the skin is a benign vascular tumor with marked inflammatory cell infiltration, which exhibits a high tendency to persist and frequently recurs after resection. So far, the underlying pathogenesis is largely elusive.

OBJECTIVES

To identify genetic alterations by next-generation-sequencing and/or droplet digital PCR (ddPCR) in cutaneous EH.

METHODS

DNA and RNA from an EH lesion of an index patient were subjected to whole genome and RNA sequencing. Multiplex PCR-based panel sequencing of genomic DNA isolated from archival formalin-fixed paraffin-embedded (FFPE) tissue of 18 cutaneous EH patients was performed. ddPCR was used to confirm mutations.

RESULTS

We identified somatic mutations in genes of the MAPK pathway (MAP2K1 and KRAS) in cutaneous EH biopsies. By ddPCR we could confirm the recurrent presence of activating, low-frequency mutations affecting MAP2K1. In total, 9 out of 18 analyzed patients showed activating MAPK pathway mutations, which were mutually exclusive. Comparative analysis of tissue areas enriched for lymphatic infiltrate or aberrant endothelial cells, respectively, revealed an association of these mutations with the presence of endothelial cells.

CONCLUSIONS

Taken together, our data suggest that EH shows somatic mutations in genes of the MAPK pathway which might contribute to the formation of this benign tumor.

Posttraumatic Vascular Anomalies in Hand Surgery-A Case-based Approach

The field of vascular anomalies (VA) has been subject to changes during the last few decades. The current classification of the International Society for the Study of Vascular Anomalies (ISSVA) offers a simple diagnostic structure. Hand surgeons commonly appear to have limited exposure to VA. Already recognized for more than 120 years, pyogenic granuloma (PG) is by far the most commonly described VA by different disciplines with accordingly diverse treatment strategies and theories behind it. Arteriovenous fistula (AVF), venous aneurysms (VAN), and venous malformations (VM) are, however, rare in hand surgery. With a compilation of four illustrative cases of posttraumatic entities such as AVF, VAN, VM, and PG, we would like to highlight possible daily exposure to VA in the general hand surgery practice. We discuss diagnostic and therapeutic options as well as the current literature with focus on posttraumatic VA.

Genetic Basis and Therapies for Vascular Anomalies

Vascular and lymphatic malformations represent a challenge for clinicians. The identification of inherited and somatic mutations in important signaling pathways, including the PI3K (phosphoinositide 3-kinase)/AKT (protein kinase B)/mTOR (mammalian target of rapamycin), RAS (rat sarcoma)/RAF (rapidly accelerated fibrosarcoma)/MEK (mitogen-activated protein kinase kinase)/ERK (extracellular signal-regulated kinases), HGF (hepatocyte growth factor)/c-Met (hepatocyte growth factor receptor), and VEGF (vascular endothelial growth factor) A/VEGFR (vascular endothelial growth factor receptor) 2 cascades has led to the evaluation of tailored strategies with preexisting cancer drugs that interfere with these signaling pathways. The era of theranostics has started for the treatment of vascular anomalies. Registration: URL: https://www.clinicaltrialsregister.eu; Unique identifier: 2015-001703-32.

Polidocanol Sclerotherapy for the Treatment of Pyogenic Granuloma in Children

BACKGROUND

Pyogenic granuloma (PG) is a benign vascular lesion that is commonly observed in the skin and mucosa. Sclerotherapy is the first-line conservative treatment option for PG.

OBJECTIVE

This retrospective study aimed to evaluate the efficacy of sclerotherapy with 1.0% polidocanol for the treatment of PG.

MATERIALS AND METHODS

All patients who were clinically diagnosed with PG consecutively at the Pediatric Outpatient Service of Qilu Children's Hospital of Shandong University from March 2018 to October 2019 received sclerotherapy with 1.0% polidocanol.

RESULT

The procedure resulted in the complete excision of PG, with inconspicuous scars. The procedure was well-tolerated, and recurrence was not observed. Allergic reactions, cutaneous necrosis, and pigmentary changes were not observed.

CONCLUSION

Sclerotherapy with 1.0% polidocanol is considered an effective treatment for PGs in children. Early treatment was associated with a more favorable outcome.

A Rare Case of Pyogenic Granuloma in the Tooth Extraction Socket

Pyogenic granuloma (PG) refers to a common, acquired, benign, and vascular tumor that arises in tissues such as the skin and mucous membranes. However, it is extremely rare for PG to arise from an empty socket after tooth extraction. Herein, we describe a rare case of PG that arose from the empty extraction socket of the second molar adjacent to a dentigerous cyst of the left mandibular wisdom tooth in a 57-year-old man. The patient's second molar was extracted during the same procedure in which the wisdom tooth and cyst were removed. Subsequently, at 42 days after surgery, an exophytic mass was found in the socket of the second molar. An excisional biopsy was performed, and the histopathological diagnosis was PG. Since the PG recurred 90 days after the surgery, a complete excision with bone curettage was performed. During the 12 months of follow-up, there has been no recurrence observed. In conclusion, as tooth extraction is a routine dental practice, clinicians should be aware that PGs can also develop from an extraction socket.

Aberrant cytoplasmic connexin43 expression as a helpful marker in vascular neoplasms

BACKGROUND

Gap junctions consisting of connexins (Cx) are fundamental in controlling cell proliferation, differentiation, and cell death. Cx43 is the most broadly expressed Cx in humans and is attributed an important role in skin tumor development. Its role in cutaneous vascular neoplasms is yet unknown.

METHODS

Fifteen cases each of cutaneous angiosarcoma (cAS), Kaposi sarcoma (KS), and cherry hemangioma (CH) were assessed by immunohistochemistry for expression of Cx43. Expression pattern, intensity, and percentage of positively stained cells were analyzed. Solid basal cell carcinomas served as positive and healthy skin as negative controls.

RESULTS

Most cases of cAS presented with a strong Cx43 staining of almost all tumor cells, whereas endothelia of KS showed medium expression and CH showed mostly weak expression. In comparison with KS or cAS, the staining intensity of CH was significantly lower (P ≤ 0.001). All tissue sections of both cAS and KS were characterized by a mostly diffuse, cytoplasmic staining pattern of the vascular endothelia. None of those showed nuclear staining.

CONCLUSION

The high-to-intermediate expression of Cx43 observed in all cases of cAS and KS suggests that this Cx may play a role in the development of malignant vascular neoplasms and serve as a helpful diagnostic marker.

GNA14, GNA11, and GNAQ Mutations Are Frequent in Benign but Not Malignant Cutaneous Vascular Tumors

Cutaneous vascular tumors consist of a heterogeneous group of benign proliferations, including a range of hemangiomas and vascular malformations, as well as heterogeneous groups of both borderline and malignant neoplasms such as Kaposi’s sarcoma and angiosarcomas. The genetics of these tumors have been assessed independently in smaller individual cohorts making comparisons difficult. In our study, we analyzed a representative cohort of benign vascular proliferations observed in a clinical routine setting as well as a selection of malignant vascular proliferations. Our cohort of 104 vascular proliferations including hemangiomas, malformations, angiosarcomas and Kaposi’s sarcoma were screened by targeted next-generation sequencing for activating genetic mutations known or assumed to be potentially relevant in vascular proliferations. An association analysis was performed for mutation status and clinico-pathological parameters. Frequent activating hotspot mutations in GNA genes, including GNA14 Q205, GNA11 and GNAQ Q209 were identified in 16 of 64 benign vascular tumors (25%). GNA gene mutations were particularly frequent (52%) in cherry (senile) hemangiomas (13 of 25). In angiosarcomas, activating RAS mutations (HRAS and NRAS) were identified in three samples (16%). No activating GNA or RAS gene mutations were identified in Kaposi’s sarcomas. Our study identifies GNA14 Q205, GNA11 and GNAQ Q209 mutations as being the most common and mutually exclusive mutations in benign hemangiomas. These mutations were not identified in malignant vascular tumors, which could be of potential diagnostic value in distinguishing these entities.

Cutaneous and hepatic vascular lesions due to a recurrent somatic GJA4 mutation reveal a pathway for vascular malformation

The term “cavernous hemangioma” has been used to describe vascular anomalies with histology featuring dilated vascular spaces, vessel walls consisting mainly of fibrous stromal bands lined by a layer of flattened endothelial cells, and an irregular outer rim of interrupted smooth muscle cells. Hepatic hemangiomas (HHs) and cutaneous venous malformations (VMs) share this histologic pattern, and we examined lesions in both tissues to identify genetic drivers. Paired whole-exome sequencing (WES) of lesional tissue and normal liver in HH subjects revealed a recurrent GJA4 c.121G>T (p.Gly41Cys) somatic mutation in four of five unrelated individuals, and targeted sequencing in paired tissue from 9 additional HH individuals identified the same mutation in 8. In cutaneous lesions, paired targeted sequencing in 5 VMs and normal epidermis found the same GJA4 c.121G>T (p.Gly41Cys) somatic mutation in three. GJA4 encodes gap junction protein alpha 4, also called connexin 37 (Cx37), and the p.Gly41Cys mutation falls within the first transmembrane domain at a residue highly conserved among vertebrates. We interrogated the impact of the Cx37 mutant via lentiviral transduction of primary human endothelial cells. We found that the mutant induced changes in cell morphology and activated serum/glucocorticoid-regulated kinase 1 (SGK1), a serine/threonine kinase known to regulate cell proliferation and apoptosis, via non-canonical activation. Treatment with spironolactone, an inhibitor of angiogenesis, suppressed mutant SGK1 activation and reversed changes in cell morphology. These findings identify a recurrent somatic GJA4 c.121G>T mutation as a driver of hepatic and cutaneous VMs, revealing a new pathway for vascular anomalies, with spironolactone a potential pathogenesis-based therapy.

Oral pyogenic granuloma: An 18-year retrospective clinicopathological and immunohistochemical study

BACKGROUND

Pyogenic granuloma (PG) is a lesion characterized by the proliferation of blood vessels, commonly affecting the skin and the mouth. We aimed to compare clinical, microscopic, and immunohistochemical features of the two types of oral PG: lobular capillary hemangioma (LCH) and non-LCH (NLCH).

METHODS

Epidemiological and clinical data from 2000 to 2018 were collected from the archives of our institution, and histopathological sections of PG were reviewed. Immunohistochemical analyses (CD34, D2-40, SMA, mast cell, and Ki-67) were performed in 34 cases.

RESULTS

Sixty-two LCH and 107 non-LCH samples were included. The mean (±SD) age of the patients was 38.59 ± 16.96 years; 55.62% were female; 39.64% of cases occurred in the gingiva, 44% of the nodules were pedunculated, and 13.02% of patients reported a history of trauma. NLCH was more prevalent among older patients than LCH. The most prevalent site of LCH was the lips, while NLCH occurred more in the gingiva (P < 0.05). Epithelial atrophy, microvessels, SMA-positive areas, and Ki-67-positive nuclei were more prevalent in LCH (P < 0.05).

CONCLUSIONS

PG accounted for 2.25% of lesions archived in the pathology service and most cases were NLCH. LCH and NLCH exhibited clinicopathological differences in terms of age, site, epithelial atrophy, vascularization, and proliferation rate.

Cell Populations Expressing Stemness-Associated Markers in Vascular Anomalies

Treatment of vascular anomalies (VAs) is mostly empirical and, in many instances unsatisfactory, as the pathogeneses of these heterogeneous conditions remain largely unknown. There is emerging evidence of the presence of cell populations expressing stemness-associated markers within many types of vascular tumors and vascular malformations. The presence of these populations in VAs is supported, in part, by the observed clinical effect of the mTOR inhibitor, sirolimus, that regulates differentiation of embryonic stem cells (ESCs). The discovery of the central role of the renin-angiotensin system (RAS) in regulating stem cells in infantile hemangioma (IH) provides a plausible explanation for its spontaneous and accelerated involution induced by β-blockers and ACE inhibitors. Recent work on targeting IH stem cells by inhibiting the transcription factor SOX18 using the stereoisomer R(+) propranolol, independent of β-adrenergic blockade, opens up exciting opportunities for novel treatment of IH without the β-adrenergic blockade-related side effects. Gene mutations have been identified in several VAs, involving mainly the PI3K/AKT/mTOR and/or the Ras/RAF/MEK/ERK pathways. Existing cancer therapies that target these pathways engenders the exciting possibility of repurposing these agents for challenging VAs, with early results demonstrating clinical efficacy. However, there are several shortcomings with this approach, including the treatment cost, side effects, emergence of treatment resistance and unknown long-term effects in young patients. The presence of populations expressing stemness-associated markers, including transcription factors involved in the generation of induced pluripotent stem cells (iPSCs), in different types of VAs, suggests the possible role of stem cell pathways in their pathogenesis. Components of the RAS are expressed by cell populations expressing stemness-associated markers in different types of VAs. The gene mutations affecting the PI3K/AKT/mTOR and/or the Ras/RAF/MEK/ERK pathways interact with different components of the RAS, which may influence cell populations expressing stemness-associated markers within VAs. The potential of targeting these populations by manipulating the RAS using repurposed, low-cost and commonly available oral medications, warrants further investigation. This review presents the accumulating evidence demonstrating the presence of stemness-associated markers in VAs, their expression of the RAS, and their interaction with gene mutations affecting the PI3K/AKT/mTOR and/or the Ras/RAF/MEK/ERK pathways, in the pathogenesis of VAs.

An Uncommon Presentation of Pyogenic Granuloma

Benign vascular neoplasms are common clinical problems encountered in the practice of primary care. Pyogenic granulomas are one of the most common benign vascular lesions in young adults. Although the physiopathological mechanism for the development of this condition is still not well understood, it has been commonly associated with several triggers such as treatment with retinoids, biological agents, invasive cutaneous therapies and trauma. The development of pyogenic granulomas on sites of vascular malformations like port wine stains has been described in the literature to occur rarely. Most of these types of cases have been studied to occur in the setting of pregnancy and after cryotherapy or pulsated laser therapy. The aim of this article is to present the case of a 21-year-old man with a recent appearance of a pyogenic granuloma within an underlying port wine stain in the posterior cervical region without any history of triggers or risk factors. Excision of the vascular lesion was done, and histopathological report confirmed the diagnosis. The objective of this manuscript is to discuss the possible mechanisms involved in the development of this uncommon presentation and to summarize the current literature related to this clinical scenario.

Congenital hepatic hemangiomas: Clinical, histologic, and genetic correlation

BACKGROUND

The guide for monitoring and treatment of congenital hepatic hemangiomas (CHH) will depend on the subtype and the postnatal clinical behavior. Our aim is to present a series of CHH and characterize its clinical, histologic and genetic correlation, compared to cutaneous congenital hemangiomas (CCH).

MATERIAL AND METHODS

A retrospective review of CHH patients diagnosed between 1991 and 2018 was performed. Clinical, morphological and histological data were analyzed and deep high-throughput sequencing was performed.

MAIN RESULTS

Sixteen patients with CHH were included. Five patients were followed up with serial ultrasounds while pharmacological treatment (corticosteroids and propranolol) was decided in five. Surgical resection was performed in five owing to hemorrhage and suspicion of malignancy, and the last patient underwent embolization. Histologic analysis was available in 7 patients and confirmed CHH, showing two different histological patterns that could be associated with the presence of somatic pathogenic variants in GNAQ and/or PIK3CA detected in the genetic testing. Review of 7 samples of CCH revealed some histologic differences compared to CHH.

CONCLUSION

CHH resemble its cutaneous homonym with similar clinical behavior. Histologic analysis can differentiate two subgroups while genetic testing can confirm mutations in GNAQ and in PIK3CA in a subset of CHH.

TYPE OF STUDY

Treatment study.

LEVEL OF EVIDENCE

IV.

The molecular pathophysiology of vascular anomalies: Genomic research

Vascular anomalies are congenital localized abnormalities that result from improper development and maintenance of the vasculature. The lesions of vascular anomalies vary in location, type, and clinical severity of the phenotype, and the current treatment options are often unsatisfactory. Most vascular anomalies are sporadic, but patterns of inheritance have been noted in some cases, making genetic analysis relevant. Developments in the field of genomics, including next-generation sequencing, have provided novel insights into the genetic and molecular pathophysiological mechanisms underlying vascular anomalies. These insights may pave the way for new approaches to molecular diagnosis and potential disease-specific therapies. This article provides an introduction to genetic testing for vascular anomalies and presents a brief summary of the etiology and genetics of vascular anomalies.

Mosaicism in genodermatoses

Genodermatoses are inherited disorders presenting with cutaneous manifestations with or without the involvement of other systems. The majority of these disorders, particularly in cases that present with a cutaneous patterning, may be explained in the context of genetic mosaicism. Despite the barriers to the genetic analysis of mosaic disorders, next-generation sequencing has led to a substantial progress in understanding their pathogenesis, which has significant implications for the clinical management and genetic counseling. Advances in paired and deep sequencing technologies in particular have made the study of mosaic disorders more feasible. In this review, we provide an overview of genetic mosaicism as well as mosaic cutaneous disorders and the techniques required to study them.

IGF2BP3 (IMP3) expression in angiosarcoma, epithelioid hemangioendothelioma, and benign vascular lesions

Background

Insulin-like growth factor-2 messenger RNA-binding protein 3 (IGF2BP3 or IMP3) is an oncofetal protein that is expressed in various cancer types, and its expression is often associated with poor prognosis. IGF2BP3 expression has not been fully settled in vascular lesions.

Methods

We evaluated the expression of IGF2BP3 in malignant (angiosarcoma and epithelioid hemangioendothelioma [EHE]) and benign (hemangioma, granulation tissue cappilaries, and pyogenic granuloma) vascular lesions using immunohistochemistry. IGF2BP3 expression was scored as negative (0% of endothelial/neoplastic cells), equivocal (1–25%), or positive (> 26%).

Results

Eight of 30 (26.7%) cases of angiosarcoma and two of five (40%) cases of epithelioid hemangioendothelioma were positive for IGF2BP3. In contrast, hemangiomas (10 cases) and granulation tissue capillaries (12 cases) were all negative for IGF2BP3, and some cases of pyogenic granuloma (six of 14 cases) was scored as equivocal. In angiosarcoma, IGF2BP3 expression was independent of age, gender, location, morphological pattern, prognosis, presence of metastatic foci, and PD-L1 expression.

Conclusions

IGF2BP3 is a useful marker to distinguish between malignant and benign vascular lesions.

New and evolving concepts of melanocytic nevi and melanocytomas

In daily clinical practice melanocytic nevi are commonly encountered. Traditionally, both benign and malignant melanocytic tumors have been sub-classified by their histopathologic characteristics with differing criteria for malignancy applied to each group. Recently, many of the mutations that initiate nevus formation have been identified and specific sets of mutations are found in different subtypes of nevi. Whereas a single mutation appears sufficient to initiate a nevus, but is not enough to result in melanoma, specific combinations of mutations have been identified in some melanocytic tumors that are regarded to be of low biologic potential. The term "melanocytoma" has recently been proposed by the World Health Organization to describe those tumors that demonstrate genetic progression beyond the single mutations that are found in nevi but are not frankly malignant. Melanocytomas occupy intermediate genetic stages between nevus and melanoma and likely have an increased risk of malignant transformation as compared to nevi. This review provides an update on the broad spectrum of melanocytic nevi and melanocytomas and outlines their key histopathologic and genetic features.

Activation of Ras in the Vascular Endothelium Induces Brain Vascular Malformations and Hemorrhagic Stroke

Cerebrovascular malformations (CVMs) affect approximately 3% of the population, risking hemorrhagic stroke, seizures, and neurological deficits. Recently Ras mutations have been identified in a majority of brain arterio-venous malformations. We generated an endothelial-specific, inducible HRAS^V12 mouse model, which results in dilated, proliferative blood vessels in the brain, blood-brain barrier breakdown, intracerebral hemorrhage, and rapid lethality. Organoid morphogenesis models revealed abnormal cessation of proliferation, abnormalities in expression of tip and stalk genes, and a failure to properly form elongating tubes. These defects were influenced by both hyperactive PI-3' kinase signaling and altered TGF-β signaling. Several phenotypic changes predicted by the in vitro morphogenesis analysis were validated in the mouse model. These data provide a model of brain vascular malformations induced by mutant Ras and reveal insights into intersecting molecular mechanisms in the pathogenesis of brain vascular malformations.

High frequency of GNA14, GNAQ, and GNA11 mutations in cherry hemangioma: a histopathological and molecular study of 85 cases indicating GNA14 as the most commonly mutated gene in vascular neoplasms

Cherry hemangioma is the most common hemangioma in adult life. Neoplastic and non-neoplastic theories had both been proposed for its pathogenesis, but its nature is still poorly understood. We noted a significant subset of anastomosing hemangiomas and congenital hemangiomas harbored a population of small capillaries surrounded by a perivascular hyaline layer, reminiscent of the vessels seen in cherry hemangioma. Both anastomosing hemangioma and congenital hemangioma harbor recurrent mutations in exon 5 of GNAQ and its paralogues. In this study, we analyzed 68 cherry hemangiomas and 17 cherry hemangioma-like hemangiomas exhibiting additional non-classical features including markedly dilated, cavernous vessels, and/or a deep component extending to the deep dermis. By Sanger sequencing, GNAQ, GNA11, and GNA14 exon 5 mutations were identified in 12, 4, and 32 cherry hemangiomas, respectively, and 5, 3, and 3 cherry hemangioma-like hemangiomas, respectively. MassARRAY analysis detected mutations (including exon 2 GNAQ^G48V mutations) in additional 8 cherry hemangiomas and 3 cherry hemangioma-like hemangiomas. Overall, the cherry hemangiomas and cherry hemangioma-like hemangiomas had equal GNA mutation rates (82%), and GNA14 and GNAQ mutations were present in approximately half of cherry hemangiomas and cherry hemangioma-like hemangiomas, respectively. All mutations were mutually exclusive. KRAS^G12V mutation was also detected in one cherry hemangioma-like hemangioma without GNA mutations. In summary, our study demonstrated recurrent GNA14/GNAQ/GNA11 mutations were present in the majority of this very common hemangioma and established its neoplastic nature. Our results also expanded the morphological spectrum of GNA-mutated hemangiomas to include tumors composed of cavernous-like vessels and indicated GNA14 was the most commonly mutated gene in vascular tumors.

[Pyogenic granuloma with satellitosis]

A 16-year-old female developed a satellite-like recurrence of a pyogenic granuloma on her thorax 2 weeks after complete excision. Treatment with a pulsed dye laser led to a complete resolution. BRAF and RAS mutations detected in the pyogenic granuloma are considered major driver mutations. Whether these findings are also of importance for the etiopathogenesis of satellitosis is unknown. In our patient, no BRAF or NRAS mutation could be detected.

Detection of NRAS mutation in cell-free DNA biological fluids from patients with kaposiform lymphangiomatosis

Background

Kaposiform lymphangiomatosis (KLA) has recently been distinguished as a novel subtype of generalized lymphatic anomaly (GLA) with foci of spindle endothelial cells. All cases of KLA involve multiple organs and have an unfavorable prognosis. However, the molecular pathogenesis is unknown, and there are no useful biomarkers. In the present study, we performed genetic analysis to elucidate the cause of this disease and detect biomarkers for it.

Methods

We performed whole-exome sequencing of DNA samples from leukocytes and a biopsy specimen and analyzed cell-free DNA (cfDNA) from plasma and pleural effusion of patients to identify the NRAS c.182A > G (p.Q61R) mutation using the droplet digital polymerase chain reaction (ddPCR).

Results

All KLA patients (patients 1–5) had invasive and aggressive features (hemorrhagic pleural effusions, coagulation disorder, and thrombocytopenia) and characteristic findings of KLA in their pathological examinations. In whole exome sequencing for patient 1, c.182A > G missense variant (p.Q61R) in NRAS was identified in fresh frozen samples of a mass on the left chest wall at a frequency of 5% of total alleles but not in his blood leukocytes. Furthermore, the same mutation was detected in cfDNA isolated from plasma and pleural effusion by using ddPCR. ddPCR analysis of plasma/pleural effusion samples from an additional four KLA patients showed that the same mutation was detected in isolated cfDNA in three of the four, as well as in a tissue sample from one of the three plasma/effusion-positive patients that had been obtained to confirm the mutation.

Conclusion

These results provide the first evidence that NRAS oncogenic variant was identified in DNA samples from KLA patients from not only two affected lesions but also plasma and pleural effusion.

Oral pyogenic granulomas show MAPK/ERK signaling pathway activation, which occurs independently of BRAF, KRAS, HRAS, NRAS, GNA11, and GNA14 mutations

BACKGROUND

Pyogenic granuloma (PG) is a benign nodular lesion with a prominent vascular component which may affect different sites. Recently, BRAF, KRAS, HRAS, NRAS, GNA11, and GNA14 mutations were reported on PGs of the skin. The present study assessed the role of the MAPK/ERK pathway in oral PG pathogenesis.

METHODS

Mutations in hotspot regions of genes involved in the MAPK/ERK pathway activation were investigated by Sanger sequencing. The expression of phospho-ERK1/2 was evaluated by immunohistochemistry.

RESULTS

Oral PGs did not show mutations in the sequenced regions of the genes BRAF, KRAS, HRAS, NRAS, GNA11, or GNA14. Our results also showed activation of the MAPK/ERK pathway demonstrated by phospho-ERK1/2 immunohistochemical positivity.

CONCLUSIONS

Although oral PG shows MAPK/ERK pathway activation, the driver molecular event remains to be elucidated.

Cellular and molecular mechanisms of PIK3CA-related vascular anomalies

The phosphoinositide 3-kinase (PI3K) pathway is a major mediator of growth factor signaling, cell proliferation and metabolism. Somatic gain-of-function mutations in PIK3CA, the catalytic subunit of PI3K, have recently been discovered in a number of vascular anomalies. The timing and origin of these mutations remain unclear although they are believed to occur during embryogenesis. The cellular origin of these lesions likely involves endothelial cells or an early endothelial cell lineage. This review will cover the diseases and syndromes associated with PIK3CA mutations and discuss the cellular origin, pathways and mechanisms. Activating PIK3CA 'hot spot' mutations have long been associated with a multitude of cancers allowing the development of targeted pharmacological inhibitors that are FDA-approved or in clinical trials. Current and future therapeutic approaches for PIK3CA-related vascular anomalies are discussed.

Congenital cutaneous pyogenic granuloma: Report of two cases and review of the literature

Congenital cutaneous pyogenic granuloma is a rare benign vascular tumor with clinical and histopathological features similar to infantile hemangioma. It usually presents as a red, pedunculated and highly friable papule. On histopathological analysis, one can see a capillary vessel proliferation with lobular pattern and endothelial proliferation. The differential diagnosis is based on negativity of glucose transporter 1 (GLUT1) immunochemistry studies. We report two infants with congenital pyogenic granuloma, one with a unique cutaneous lesion and the other with multiple lesions affecting both skin and mucosal surfaces. These two cases highlight the importance of the differential diagnosis based on the GLUT1 immunochemistry analysis considering the distinct treatments required to these infant vascular tumors.

Genetic investigation of childhood vascular tumor biology reveals pathways for therapeutic intervention

Vascular tumors are neoplasms of endothelial cells, a significant number of which present in childhood. Recent studies have examined the mutational landscape of many subtypes of vascular tumors, identifying mutations primarily within the Ras–mitogen-activated protein kinase (MAPK) pathway and providing a unique opportunity to consider targeted therapeutics. This review will summarize the current understanding of childhood vascular tumor pathobiology.

Multifocal congenital pyogenic granuloma successfully treated with oral propranolol

Disseminated congenital pyogenic granuloma (DCPG) is an uncommon condition. Individual lesions of DCPG share clinical and histologic similarities with infantile hemangioma (IH); endothelial glucose transporter 1 (GLUT-1), which is highly expressed in IH but generally not in pyogenic granulomas (PG), is an important diagnostic tool. Treatment for DCPG remains difficult. We describe a case of DCPG effectively treated with propranolol.