title: CT Manifestations of Inflammatory Myofibroblastic Tumors (Inflammatory Pseudotumors) of the Urinary System.
abstract: OBJECTIVE
  The purpose of this study is to characterize the CT manifestations of inflammatory myofibroblastic tumors (IMTs) of the urinary system in eight patients.
  
  
  METHODS
  The CT images of eight pathologically confirmed IMTs were retrospectively reviewed. Two of the eight IMTs occurred in the kidney, and six occurred in the bladder. Seven patients underwent both unenhanced CT and contrast-enhanced CT, and one of the patients who had a bladder tumor underwent unenhanced CT only. The site, shape, size, boundary, internal structure, and enhancement pattern of the lesions were assessed.
  
  
  RESULTS
  The eight patients (five men and three women) whose CT images were reviewed were 18-77 years old (mean age, 53 years). Only one lesion was seen in each of the eight patients. The IMTs occurred at the renal parenchyma (n = 1), the renal pelvis (n = 1), or the bladder (n = 6). Their shape was either roundlike (n = 7) or round (n = 1), and their size ranged from 1.5 × 2.0 cm(2) to 3.7 × 5.2 cm(2). Tumor margins were smooth (n = 5) or lobulated (n = 3), and boundaries were clear (n = 5) or ill defined (n = 3). Unenhanced CT scans showed a low density (n = 4), isodensity (n = 3), or a slightly high density (n = 1). The density noted on the unenhanced CT scans was homogeneous (n = 7) or heterogeneous (n = 1). The contrast-enhanced scans showed ring enhancement (n = 3) or significantly heterogeneous enhancement (n = 4), and the type of enhancement was persistent (n = 6) or washout (n = 1).
  
  
  CONCLUSIONS
  IMTs in the urinary system commonly occur in the superior wall or the front wall of the bladder. The observation that polypoid nodules on the bladder walls show ring enhancement on contrast-enhanced CT may be valuable in the diagnostic imaging of IMTs of the urinary system.
authors.affiliation: 1 Department of Radiology, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou City, China.
authors.forename: Wenjie
authors.initials: W
authors.lastname: Liang
authors.affiliation: 1 Department of Radiology, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou City, China.
authors.forename: Xianyong
authors.initials: X
authors.lastname: Zhou
authors.affiliation: 1 Department of Radiology, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou City, China.
authors.forename: Shunliang
authors.initials: S
authors.lastname: Xu
authors.affiliation: 2 Department of Hepatobiliary and Pancreatic Surgery, First Affiliated Hospital, College of Medicine, Zhejiang University, 79 Qingchun Rd, Hangzhou City, Zhejiang Province 310003, China.
authors.forename: Shengzhang
authors.initials: S
authors.lastname: Lin
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D006104:Granuloma, Plasma Cell / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D014570:Urologic Diseases / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy
keywords: CT; bladder; inflammatory myofibroblastic tumor; inflammatory pseudotumor; kidney