title: CT and ultrasound features of basal cell adenoma of the parotid gland: a report of 22 cases with pathologic correlation.
abstract: OBJECTIVE
  Parotid gland BCA is a rare benign tumor. Only a few studies describing the imaging features of BCA have been published. This study investigated CT and sonography characteristics of BCA of the parotid gland.
  
  
  METHODS
  Demographics of patients with BCA were evaluated, and lesion characteristics of CT (n = 22) and sonography (n = 20) were reviewed. These cases were grouped into 3 types: type 1 tumors, located at the superficial region of superficial lobe of the parotid gland; type 2 tumors, located at the deeper region of superficial lobe; and type 3 tumors, located in the deep lobe. Imaging findings were correlated with pathology.
  
  
  RESULTS
  Sixteen patients (73%) were female and 6 (27%) were male. The mean age was 51.5 years (SD 10.2; range 32-73). The size of the tumors was less than 30 mm. The sizes of type 1, type 2, and type 3 tumors were 11.4 ± 3.29 mm, 19.3 ± 5.44 mm, and 26 ± 3.6 mm, respectively. The CT attenuation increase was 64.5 ± 19 HU on contrast CT. The type 1 tumors were solid (11/11), showed homogeneous or slightly heterogeneous enhancement on CT, and were homogeneously or slightly heterogeneously hypoechoic on sonography. Cystic changes tended to occur in type 2 (7/8) or type 3 (2/3) tumors, which showed obvious heterogeneous attenuation on CT and anechoic on sonography.
  
  
  CONCLUSIONS
  The BCA tends to be small and shows early intense enhancement. The solid tumor is common in the superficial region of the parotid gland, and cystic lesions occur mostly in the deeper parts of the superficial lobe or in the deep lobe.
authors.affiliation: Department of Radiology, ZheJiang Cancer Hospital, Hang Zhou, People’s Republic of China.
authors.forename: L
authors.initials: L
authors.lastname: Shi
authors.forename: Y-X J
authors.initials: YX
authors.lastname: Wang
authors.forename: C
authors.initials: C
authors.lastname: Yu
authors.forename: F
authors.initials: F
authors.lastname: Zhao
authors.forename: P-D
authors.initials: PD
authors.lastname: Kuang
authors.forename: G-L
authors.initials: GL
authors.lastname: Shao
mesh_terms: D000236:Adenoma / Q000175:diagnosis*; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010307:Parotid Neoplasms / Q000175:diagnosis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013223:Statistics as Topic; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014463:Ultrasonography / Q000379:methods*