title: [Malignant epithelial parotid tumors: CT imaging and histopathologic correlation].
abstract: OBJECTIVE
  Malignant epithelial parotid tumors have various histopathologic types. Computed tomography (CT) has been widely used to detect parotid masses. This study was to analyze CT features of malignant epithelial parotid tumors to evaluate the diagnostic value of CT in the characterization of malignant epithelial parotid tumors.
  
  
  METHODS
  CT reports of 29 patients with malignant epithelial parotid tumors (8 at low grade and 21 at intermediate or high grade), confirmed by histopathology in Cancer Center of Sun Yat-sen University, were reviewed. The localization, contour, margin, enhancing type, homogeneity, infiltration into the adjacent structures, and lymph node metastasis detected by CT scan were compared with relevant pathologic results.
  
  
  RESULTS
  Of the 8 cases at low grade, 4 were well-differentiated mucoepidermoid carcinoma, 3 were acinic cell carcinoma, and 1 was epithelial-myoepithelial carcinoma; 3 had sharp margin, 3 had partly unsharp margin, and 2 had unsharp margin; 5 had regular contour, and 3 had irregular contour; all were enhanced obviously; 2 showed homogeneous appearance, and 6 showed inhomogeneous appearance with low-density areas; none had adjacent infiltration; 3 had lymph node metastasis. Of the 21 cases at intermediate or high grade, 5 were poorly-differentiated squamous cell carcinoma, 8 were malignant pleomorphic adenoma, 2 were adenocarcinoma, 1 was lymph-epithelial carcinoma, 4 were mucoepidermoid carcinoma, and 1 was adenoidcystic carcinoma; 5 had sharp margin, 7 had partly unsharp margin, and 9 had unsharp margin; 10 had regular contour, and 11 had irregular contour; 17 were enhanced obviously, and the 4 cases of malignant pleomorphic adenoma were enhanced slightly; 9 showed homogeneous appearance, and 12 showed inhomogeneous appearance with low-density areas; 8 had adjacent infiltration (the fat space between tumor and the parotid bed disappeared); 6 had lymph node metastasis.
  
  
  CONCLUSIONS
  To some extent, CT features of malignant epithelial parotid tumors are correlated to the differentiation of tumor cells. Moreover, tumor size and histologic subtype should be considered to make a more accurate imaging diagnosis.
authors.affiliation: State Key Laboratory of Oncology in South China, Guangzhou, Guangdong, 510060, P. R. China.
authors.forename: Jing-Xian
authors.initials: JX
authors.lastname: Shen
authors.forename: Wei-Jun
authors.initials: WJ
authors.lastname: Fan
authors.forename: Yan-Chun
authors.initials: YC
authors.lastname: Lu
authors.forename: Peng
authors.initials: P
authors.lastname: Xiao
mesh_terms: D008949:Adenoma, Pleomorphic / Q000000981:diagnostic imaging / Q000473:pathology; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002277:Carcinoma / Q000000981:diagnostic imaging* / Q000473:pathology*; D018277:Carcinoma, Mucoepidermoid / Q000000981:diagnostic imaging / Q000473:pathology; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D010306:Parotid Gland / Q000000981:diagnostic imaging / Q000473:pathology; D010307:Parotid Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D014057:Tomography, X-Ray Computed; D055815:Young Adult