RT Book, Section A1 Frieden, Ilona J. A1 Maguiness, Sheilagh M. A2 Rudolph, Colin D. A2 Rudolph, Abraham M. A2 Lister, George E. A2 First, Lewis R. A2 Gershon, Anne A. SR Print(0) ID 7033314 T1 Chapter 364. Vascular Tumors and Malformations T2 Rudolph's Pediatrics, 22e YR 2011 FD 2011 PB The McGraw-Hill Companies PP New York, NY SN 978-0-07-149723-7 LK accesspediatrics.mhmedical.com/content.aspx?aid=7033314 RD 2023/04/01 AB The International Society of the Study of Vascular Anomalies (ISSVA) divided vascular anomalies into malformations or tumors, and the vast majority of vascular lesions can be classified using this schema (Table 364-1). Vascular tumors and malformations can usually be distinguished from one another based on clinical appearance and growth characteristics (Table 364-2). If diagnosis is unclear observation over time, imaging studies or even biopsy may be required.