title: Imaging characteristics of intravascular papillary endothelial hyperplasia.
abstract: OBJECTIVE
  Intravascular papillary endothelial hyperplasia (IPEH) is a soft tissue, tumor-like, benign, reactive, vascular proliferation that, although not rare, is uncommonly imaged. We report the imaging findings of intravascular papillary endothelial hyperplasia in 13 patients, highlighting characteristic imaging features.
  
  
  METHODS
  We retrospectively reviewed 13 patients with IPEH who had corresponding MR and/or ultrasound imaging. MR imaging studies were evaluated for lesion location, shape, size, signal intensity, signal heterogeneity, and enhancement. Ultrasound studies were assessed for lesion shape, size, echogenicity, heterogeneity, and vascularity. Demographic data, including patient age, gender, and clinical history were also reviewed.
  
  
  RESULTS
  Most patients (11 of 13) presented with an enlarging mass. The age range was 10-72 years (mean 46) with ten females and three males. Eleven of the 13 lesions were primary IPEH without an associated preexisting vascular lesion. Ten of 13 lesions were in the superficial soft tissues, all of which were primary IPEH. Two of the three lesions in the deep tissues were secondary IPEH, arising within a preexisting vascular lesion. Lesions were small (mean 1.4 cm) and had a rounded shape. All of the primary lesions demonstrated high T2 signal peripherally and variable T2 signal centrally, with most demonstrating superficial location (91 %), peripheral enhancement (89 %) and associated dominant vessel (73 %). The five lesions evaluated by ultrasound were all hypoechoic with either scattered or peripheral vascularity on Doppler.
  
  
  CONCLUSIONS
  Primary papillary endothelial hyperplasia is commonly seen in the superficial soft tissues when captured on imaging and has a characteristic imaging appearance.
authors.affiliation: Department of Radiology, Mayo Clinic, 5777 East Mayo Boulevard, Phoenix, AZ, 85054, USA.
authors.forename: Keith A
authors.initials: KA
authors.lastname: Craig
authors.affiliation: Department of Radiology, Brooke Army Medical Center, San Antonio, TX, X78234, USA.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Escobar
authors.affiliation: Department of Anatomic Pathology, Mayo Clinic, 200 1st Street SW, Rochester, MN, 55905, USA.
authors.forename: Carrie Y
authors.initials: CY
authors.lastname: Inwards
authors.affiliation: Department of Radiology, Mayo Clinic, 5777 East Mayo Boulevard, Phoenix, AZ, 85054, USA. kransdorf.mark@mayo.edu.
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Kransdorf
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D003937:Diagnosis, Differential; D004730:Endothelium, Vascular / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D006390:Hemangioendothelioma / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012983:Soft Tissue Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D014463:Ultrasonography / Q000379:methods*; D055815:Young Adult
keywords: Intravascular papillary endothelial hyperplasia; Masson lesion; Papillary endothelial hyperplasia; Soft tissue neoplasm; Vascular lesion; Vegetant intravascular hemangioendothelioma