title: Magnetic resonance imaging features of ovarian fibroma, fibrothecoma, and thecoma.
abstract: OBJECTIVE
  To retrospectively evaluate the conventional and functional (diffusion- or perfusion-weighted) magnetic resonance (MR) imaging features of ovarian fibroma, fibrothecoma, and thecoma.
  
  
  METHODS
  Histologically proven ovarian fibromas (n = 19), fibrothecomas (n = 7), and thecomas (n = 2) were reviewed (26 patients). The morphologic and signal intensity (SI) characteristics on conventional MR imaging (n = 28, all cases) were analyzed. The b 1000 signal intensity on diffusion-weighted image (DWI) (n = 22) and the time-to-signal intensity curve on perfusion-weighted image (PWI) (n = 7) were also analyzed. The presence and shape of the ipsilateral ovarian tissue surrounding the lesions were evaluated on T2-weighted image.
  
  
  RESULTS
  Twenty-two cases (79%) were predominantly solid tumor. Majority of the detected lesions exhibited the characteristic homogeneous low SI on T1- (24/28, 86%) and T2- (19/28, 68%) weighted image. Conversely, a number of lesions exhibited high SI (9/28, 32%) on T2-weighted image. Most lesions presented with a detectable ipsilateral ovary on T2-weighted image (24/28, 86%). Tumors larger than 6 cm more likely showed atypical morphology (mixed solid and cystic, cystic), atypical SI (high on T1- and T2-weighted image), and large amount ascites. Larger tumor group (>6 cm) was more likely diagnosed as fibrothecoma or thecoma than fibroma by pathology. On DWI, 16 lesions showed low b 1000 signal intensity (16/22, 73%). On PWI, all lesions showed curve type 1 or 2 (7/7, 100%), which tends to characterize benign lesions. All (16/16, 100%) pre-menopausal women had a detectable ipsilateral ovary, and six (60%) out of 10 post-menopausal women had a detectable ipsilateral ovary (p < 0.05).
  
  
  CONCLUSIONS
  Combining conventional morphologic and signal intensity characteristics with the findings from DWI or PWI might help differentiate ovarian fibroma, fibrothecoma, and thecoma from ovarian malignancy, although further prospective larger scale study using DWI and PWI is needed.
authors.affiliation: Department of Radiology, Chung-Ang University Hospital, Chung-Ang University College of Medicine, 102, Heukseok-ro, Dongjak-Gu, Seoul, 156-755, Korea.
authors.forename: Bo Mi
authors.initials: BM
authors.lastname: Chung
authors.forename: Sung Bin
authors.initials: SB
authors.lastname: Park
authors.forename: Jong Beum
authors.initials: JB
authors.lastname: Lee
authors.forename: Hyun Jeong
authors.initials: HJ
authors.lastname: Park
authors.forename: Yang Soo
authors.initials: YS
authors.lastname: Kim
authors.forename: Yoon Jin
authors.initials: YJ
authors.lastname: Oh
mesh_terms: D000328:Adult; D005260:Female; D005350:Fibroma / Q000175:diagnosis*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D010051:Ovarian Neoplasms / Q000175:diagnosis*; D013798:Thecoma / Q000175:diagnosis*