Venous Malformations

477 Vascular anomalies (birthmarks) are commonly encountered lesions and vary from tiny skin discolorations to large, devastating lesions requiring invasive interventions (Table 1).1 These lesions can involve any part of the body, but the lower extremities, particularly the foot and ankle regions, are commonly affected. A vascular anomaly in the foot or ankle usually requires treatment because of significant pain and discomfort regardless of the size of the lesion, whereas the same lesion in a different location (eg, the trunk) may be managed simply by observation and may not require treatment. It is common to see incorrect terminology used in the diagnostic work-up of vascular anomalies. A typical example is the term hemangioma or cavernous hemangioma, which is commonly used for venous malformation (VM). Also, it is common for practitioners, even pathologists, to refer to any non-neoplastic vascular lesion as an arteriovenous malformation (AVM), which causes confusion, erroneous staging, and mistreatment in some cases. Limited experience with vascular anomalies among diagnosticians also leads to less-than-ideal testing being performed during the diagnostic work-up of these patients. For example, computed tomography (CT) and noncontrast magnetic resonance imaging (MRI) do not provide any useful information in most cases. Also, using advanced imaging techniques, such as MR angiography and CT angiography, requires solid knowledge not only of vascular anomalies but also of the new technologies and imaging modalities. Currently, the rate of misdiagnosis may be higher than 50% of all patients referred to a dedicated tertiary-care medical center.2 This article aims to guide practitioners who occasionally encounter vascular anomalies in the process of diagnosing these anomalies and to briefly describe the currently available treatment options. Various vascular anomalies are described in descending order of prevalence in daily practice. More information on vascular anomalies can be found at my Web site (http://www.birthmarks.us).