title: Clear cell carcinoma of the ovary: comparison of MR findings of histological subtypes.
abstract: To retrospectively compare the MR findings of histological subtypes of clear cell carcinomas (CCCs) of the ovary.
  
  
  
  This single-center retrospective study was approved by the institutional review board, and the requirement for informed consent was waived. Between April 2005 and August 2015, we found 51 consecutive patients with histopathologically proven CCCs. Among them, 44 CCCs in 37 patients who underwent preoperative MR imaging were included. CCCs were pathologically divided into three subgroups: (1) four clear cell adenofibroma-associated CCCs, (2) 21 endometriosis-associated CCCs, and (3) 19 indeterminate CCCs. The statistical tests were used to compare the frequency of qualitative assessments and value of quantitative measurements among the histological subtypes.
  
  
  
  On T2-weighted images, hypointense areas within solid components were more frequently observed in clear cell adenofibroma-associated CCCs [3/4 (75%)] than in the remaining CCCs [1/40 (3%)] (p < 0.01), and the signal intensity ratios (SIRs) of solid components were significantly lower in clear cell adenofibroma-associated CCCs (0.27 ± 0.13) than in the remaining CCCs (0.61 ± 0.18) (p < 0.01). On T1-weighted images, hyperintensities of cystic components were more frequently observed in the endometriosis-associated CCCs [17/21 (81%)] than in the remaining CCCs [5/20 (25%)] (p < 0.01), and the SIRs of cystic components were significantly higher in endometriosis-associated CCCs (2.99 ± 1.51) than in the remaining CCCs (1.82 ± 1.10) (p < 0.01).
  
  
  
  MR features may help differentiate between adenofibroma-associated and endometriosis-associated CCC.
authors.affiliation: Department of Radiology, Gifu University School of Medicine, 1-1 Yanagido, Gifu, 501-1194, Japan. hkato@gifu-u.ac.jp.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Kato
authors.affiliation: Department of Pathology, Gifu University School of Medicine, Gifu, Japan.
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Hatano
authors.affiliation: Department of Obstetrics and Gynecology, Gifu University School of Medicine, Gifu, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Makino
authors.affiliation: Department of Obstetrics and Gynecology, Gifu University School of Medicine, Gifu, Japan.
authors.forename: Tatsuro
authors.initials: T
authors.lastname: Furui
authors.affiliation: Department of Obstetrics and Gynecology, Gifu University School of Medicine, Gifu, Japan.
authors.forename: Ken-Ichirou
authors.initials: KI
authors.lastname: Morishige
authors.affiliation: Department of Radiology, Gifu University School of Medicine, 1-1 Yanagido, Gifu, 501-1194, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Matsuo
mesh_terms: D018262:Adenocarcinoma, Clear Cell / Q000000981:diagnostic imaging* / Q000473:pathology*; D000232:Adenofibroma / Q000000981:diagnostic imaging / Q000473:pathology; D000328:Adult; D000368:Aged; D003287:Contrast Media; D003937:Diagnosis, Differential; D004715:Endometriosis / Q000000981:diagnostic imaging / Q000473:pathology; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D010051:Ovarian Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D012189:Retrospective Studies
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA
keywords: Adenofibroma; Clear cell carcinoma; Endometriosis; MRI; Ovary