====== Venous malformation ======


Venous [[malformation]]s (VMs) are a type of type of [[vascular malformation]] that results from [[vein]]s that have developed abnormally, which stretch or enlarge over time. VMs can be extremely painful and sensitive. A VM usually looks like a bluish discoloration. It can be a single lesion or it may be one of many.
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Gain-of-function [[PIK3CA]] pathogenic variants have been identified in overgrowth syndromes collectively termed "[[PIK3CA-related overgrowth spectrum]]" (PROS). There are no previously reported cases of cerebrovascular [[venous malformation]]s in PROS syndromes, though somatic activating PIK3CA variants have been identified in extracranial venous malformation. This study was approved by the Institutional Review Board at Boston Children's Hospital. A 14-year-old female mosaic for the de novo p.R108H pathogenic variant in the PIK3CA gene was found to have a large tumor involving the [[superior sagittal sinus]] with mass effect on the [[motor cortex]] most consistent with a [[parafalcine meningioma]]. She underwent surgical resection with pathology demonstrating a venous malformation. PIK3CA pathogenic variants have been identified in nonsyndromic extracranial venous and lymphatic malformations as well in [[brain tumor]]s, including [[glioma]] and [[meningioma]]. However, [[PIK3CA]] variants have not previously been identified in purely intracranial venous malformations. This distinction is relevant to treatment decisions, given that [[mTOR inhibitor]]s may provide an alternative option for noninvasive therapy in cases of suspected [[venous malformation]]
((Filippidis A, Lidov H, Al-Ibraheemi A, See AP, Srivastava S, Orbach DB, Fehnel KP. Intracranial venous malformation masquerading as a meningioma in PI3KCA-related overgrowth spectrum disorder. Am J Med Genet A. 2021 Dec 2. doi: 10.1002/ajmg.a.62570. Epub ahead of print. PMID: 34854542.)).
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[[Orbital Venous Malformation]]