Congenital Vascular Tumors

A 16-year retrospective study of vascular anomalies in the head and neck region

Depending on the diagnostic modality, the classification of vascular anomalies varies and so does the nomenclature. The 'International Society for the Study of Vascular Anomalies' (ISSVA) is the most widely accepted classification in the literature and is mainly based on the radiologic and clinical presentation. The aim of this article is to review the clinical practice of diagnosis and treatment of vascular anomalies in the head and neck region in a university hospital, with special focus on the nomenclature. All patients with a vascular anomaly presenting to the department of oral and maxillofacial surgery were reviewed in a retrospective manner. Nomenclature, diagnostic process, lesion characteristics, treatment and outcome were examined. The lesions were (re)classified according to the ISSVA classification. A total of 185 patients were identified, of which 12.4% (n = 23) had a congenital anomaly. After reclassification, the most common lesions were venous malformations (n = 47, 25.4%), followed by lobular capillary hemangiomas (n = 17, 9.2%). A group of 39 anomalies could not be further specified. One hundred and one patients (54,6%) received treatment, of which 93 were treated surgically (92,1% of treated patients). Endovascular treatment was considered in 41 patients but applied in only eight. This strict selection led to a low a complication rate. We provide an overview of the clinical practice in the management of vascular anomalies in a university hospital. The histology report is a source of miscommunication because clinicians use the ISSVA classification, while pathologists use the WHO classification. Every professional involved should be aware of the differences in classification and nomenclature.

MEK inhibition reduced vascular tumor growth and coagulopathy in a mouse model with hyperactive GNAQ

Activating non-inherited mutations in the guanine nucleotide-binding protein G(q) subunit alpha (GNAQ) gene family have been identified in childhood vascular tumors. Patients experience extensive disfigurement, chronic pain and severe complications including a potentially lethal coagulopathy termed Kasabach-Merritt phenomenon. Animal models for this class of vascular tumors do not exist. This has severely hindered the discovery of the molecular consequences of GNAQ mutations in the vasculature and, in turn, the preclinical development of effective targeted therapies. Here we report a mouse model expressing hyperactive mutant GNAQ in endothelial cells. Mutant mice develop vascular and coagulopathy phenotypes similar to those seen in patients. Mechanistically, by transcriptomic analysis we demonstrate increased mitogen activated protein kinase signaling in the mutant endothelial cells. Targeting of this pathway with Trametinib suppresses the tumor growth by reducing vascular cell proliferation and permeability. Trametinib also prevents the development of coagulopathy and improves mouse survival.

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.

Pediatric Penile Non-Involuting Congenital Hemangioma With an Associated Pyogenic Granuloma: Surgical Management of a Rare Vascular Anomaly

Vascular anomalies include both tumors and malformations. Infantile hemangiomas are the most common benign vascular tumor of infancy that proliferate after birth and eventually involute. By contrast, congenital hemangiomas are formed at birth and are categorized into three groups: rapidly involuting, partially-involuting, and non-involuting congenital hemangiomas (NICH). NICH do not regress and grow with age. Pyogenic granulomas, another acquired vascular tumor, develop over vascular lesions and cause bleeding. Primary treatment options for NICH and pyogenic granulomas are surgical resection. Here, we report a case of a NICH with a co-existing pyogenic granuloma involving the penile shaft and scrotum treated surgically.

MiR-206 promotes extracellular matrix accumulation and relieves infantile hemangioma through targeted inhibition of DNMT3A

MiR-206 is abnormally expressed in infant hemangioma endothelial cells (HemECs), but the mechanism is not clear. We explored the intervention of miR-206 in HemECs in relation to extracellular matrix (ECM) metabolism. We selected 48 cases of infantile hemangioma (IH) from volunteer organizations. After the isolated and extracted HemECs were interfered with overexpressed or silenced miR-206, the effects of miR-206 on the proliferation, migration and invasion of HemECs were examined through basic cell function experiments. The expression differences of miR-206, DNA Methyltransferase 3A (DNMT3A) and ECM-related genes were analyzed as needed by qRT-PCR or Western blot. TargetScan and dual-luciferase experiments were applied to predict and confirm the binding relationship between miR-206 and DNMT3A. The correlation between miR-206 and DNMT3A was analyzed in IH tissues by Pearson correlation coefficient, and further confirmed in HemECs by conducting rescue experiments. A nude mouse model of xenograft tumor was constructed to verify the results of in vitro experiments. MiR-206, which was downregulated in proliferative hemangioma, suppressed the malignant development of HemECs by regulating ECM-related genes. As the target gene of miR-206, DNMT3A was high-expressed in IH tissues and was negatively correlated with miR-206. Overexpressed DNMT3A counteracted the inhibitory effect of miR-206 mimic on HemECs and its regulatory effect on ECM. The results of in vivo experiments were consistent with those from cell experiments. Thus, miR-206 could promote ECM accumulation through targeted inhibition of DNMT3A, further inhibiting the malignant development of HemECs and relieving IH.

Infantile and congenital hemangiomas

Infantile hemangiomas (IHs) are the most common benign tumors of infancy. They typically appear after birth and undergo a period of rapid growth, followed by a gradual period of involution. Although the majority of IHs do not requirement treatment, oral propranolol is the first-line therapy for lesions that are at risk for life-threatening complications, functional impairment, ulceration, or permanent disfigurement. Rarely, IHs can be associated with structural anomalies. Congenital hemangiomas (CHs) are a distinct clinical entity, caused by a point mutation in GNAQ or GNA11. These lesions are typically present at birth and display a wide spectrum of clinical presentations. CHs can be distinguished from IHs by their unique histologic and radiographic features. Given the high-flow vascularity of CHs, surgical excision may be indicated due to the high risk of bleeding.

Silencing microRNA-210 in Hypoxia-Induced HUVEC-Derived Extracellular Vesicles Inhibits Hemangioma

BACKGROUND

Hemangioma (Hem) is a benign tumor commonly seen in infancy with a relative high morbidity. Human umbilical vein endothelial cell (HUVEC)-derived extracellular vesicles (EVs) are actively participated in Hem. Therefore, this study is designed to figure out the underlying mechanism of HUVEC-derived EVs in Hem.

METHODS

Initially, EVs were separated from HUVECs and identified. HUVEC-derived EVs in normoxia or hypoxia were then cultivated with Hem endothelial cells (HemECs) to test the proliferation, apoptosis, and migration of HemECs. Microarray analysis was performed to select microRNAs (miRs) with differential expression. miR-210 in hypoxia-induced HUVECs was silenced, and the relevant EVs were extracted and then co-cultured with HemECs to perform biological effect experiments. Then, the target relation between miR-210 and homeobox A9 (HOXA9) was identified by the dual luciferase reporter gene assay and RNA immunoprecipitation assay. Moreover, xenograft transplantation was also applied to confirm the in vitro experiments.

RESULTS

Hypoxia-induced HUVECs promoted release of EVs, which were absorbed by HemECs. Hypoxia-induced HUVEC-EVs promoted HemEC proliferation and migration and inhibited apoptosis. miR-210 from the hypoxia-induced HUVEC-EVs was highly expressed and promoted HemEC growth. Silencing miR-210 expression in the hypoxia-induced HUVEC-EVs suppresses Hem development in vivo. In addition, miR-210 targeted HOXA9.

CONCLUSION

Silencing miR-210 in HUVEC-derived EVs could suppress Hem by targeting HOXA9. This investigation may provide novel insights for Hem treatment.