title: [Cystic parotid gland lesion evaluation].
abstract: OBJECTIVE
  We evaluated differential diagnoses of cystic parotid gland lesions and the efficacy of preoperative diagnosis.
  
  
  METHODS
  Of 191 parotid gland nodules resected between January 2003 and October 2008, 167 (87%) were benign and 24 (13%) malignant. Thirty-five parotid gland nodules whose components were almost cystic were enrolled in this study. All cystic lesions were retrospectively evaluated with respect to preoperative diagnostic examinations and histopathological confirmed diagnosis. Cystic components in surgical specimens were also evaluated histopathologically. The relationships with magnetic resonance imaging (MRI) findings and histopathological confirmed diagnosis were studied.
  
  
  RESULTS
  Of 35 cystic lesions, 11 were complete cystic masses and had no mural nodules, while remaining 24 were incomplete and had mural nodules. Histopathological examinations showed that 5 were nonneoplastic, 27 were cystic degenerations of benign tumors, and 3 were cystic degenerations of malignant tumors. In the 11 complete cysts, preoperative diagnosis could not be made using any modality, whether with FNAC, salivary scintigraphy, or 67-gallium citrate scintigraphy. Of 24 incomplete cysts, only 9 cystic Warthin tumors were diagnosed correctly before surgery. Studies of cystic components in MRI and histopathology suggested that hemorrhagic degeneration of malignant tumors should be kept in mind for cystic lesions showing hemorrhagic portions.
  
  
  CONCLUSIONS
  Cystic parotid gland lesions are difficult to diagnose correctly before surgery, but the evaluation of cystic components by MRI and FNAC is helpful in differentiating between benign and malignant tumors.
authors.affiliation: Department of Otolaryngology, Kobe City Medical Center General Hospital, Kobe.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kikuchi
authors.forename: Shogo
authors.initials: S
authors.lastname: Shinohara
authors.forename: Keizo
authors.initials: K
authors.lastname: Fujiwara
authors.forename: Shin-Ya
authors.initials: SY
authors.lastname: Hori
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Tona
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yamazaki
authors.forename: Risa
authors.initials: R
authors.lastname: Kurihara
authors.forename: Yuji
authors.initials: Y
authors.lastname: Kanazawa
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Naito
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003560:Cysts / Q000175:diagnosis* / Q000473:pathology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010305:Parotid Diseases / Q000175:diagnosis* / Q000473:pathology; D012189:Retrospective Studies