title: Differentiation of pleomorphic adenoma and Warthin's tumor of the parotid gland: ultrasonographic features.
abstract: BACKGROUND
  Parotid tumor is an uncommon neoplasm. Only a few studies describing the sonographic features of pleomorphic adenomas and Warthin's tumors have been published, and most of those reports are based on a relatively small number of cases.
  
  
  OBJECTIVE
  To define the sonographic characteristics of pleomorphic adenoma and Warthin's tumor in the parotid gland.
  
  
  METHODS
  We retrospectively evaluated the sonographic features of 77 pleomorphic adenomas in 70 patients and 93 Warthin's tumors in 61 patients. The features included tumor size, shape, border, echogenicity, and homogeneity, the presence of a cystic area, acoustic enhancement, and the grade and distribution of vascularization.
  
  
  RESULTS
  Lobulated lesions were observed in 49 pleomorphic adenomas and 36 Warthin's tumors. The lobulated shape was observed more frequently in pleomorphic adenomas than in Warthin's tumors (P = 0.005). Cystic areas within lesions were detected in 16 (16/77, 20.8%) pleomorphic adenomas and 42 (42/93, 45.2%) Warthin's tumors (P = 0.001). Of the pleomorphic adenomas, 77.9% had grade 0 or grade 1 vascularity, while 73.1% of Warthin's tumors had grade 2 or grade 3 vascularity (P = 0.000). Flow was peripheral in 53.2% of pleomorphic adenomas. The frequencies of central perfusion and mixed perfusion in Warthin's tumors were equal (47.3% vs. 47.3%, respectively). The differences in the vessel distribution between these two diseases was significant (P = 0.000).
  
  
  CONCLUSIONS
  Ultrasound imaging characteristics, including multiple occurrences, shape, intrinsic cystic change, and the grade and distribution of tumor vessels, can be used to differentiate pleomorphic adenomas from Warthin's tumors.
authors: Department of Diagnostic Ultrasound, Beijing Tongren Hospital, Capital Medical University, Beijing, PR China.
authors: Xueyu
authors: X
authors: Rong
authors: Department of Diagnostic Ultrasound, Beijing Tongren Hospital, Capital Medical University, Beijing, PR China qzhutr@sina.cn.
authors: Qiang
authors: Q
authors: Zhu
authors: Department of Diagnostic Ultrasound, Beijing Tongren Hospital, Capital Medical University, Beijing, PR China.
authors: Hongtao
authors: H
authors: Ji
authors: Department of Diagnostic Ultrasound, Beijing Tongren Hospital, Capital Medical University, Beijing, PR China.
authors: Jiangping
authors: J
authors: Li
authors: Department of Diagnostic Ultrasound, Beijing Tongren Hospital, Capital Medical University, Beijing, PR China.
authors: Huilian
authors: H
authors: Huang
mesh_terms: D000235:Adenolymphoma / Q000000981:diagnostic imaging*; D008949:Adenoma, Pleomorphic / Q000000981:diagnostic imaging*; D000328:Adult; D000368:Aged; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009389:Neovascularization, Pathologic / Q000000981:diagnostic imaging; D015588:Observer Variation; D010306:Parotid Gland / Q000000981:diagnostic imaging*; D010307:Parotid Neoplasms / Q000000981:diagnostic imaging*; D012189:Retrospective Studies; D014463:Ultrasonography; D055815:Young Adult
keywords: Head/neck; salivary glands; ultrasound