title: Sinonasal inverted papilloma: value of convoluted cerebriform pattern on MR imaging.
abstract: OBJECTIVE
  A convoluted cerebriform pattern (CCP) has been reported as a valuable MR imaging feature of inverted papilloma (IP). The purpose of this study was to validate the usefulness of CCP for distinguishing IP from various malignant sinonasal tumors in a relatively large number of patients.
  
  
  METHODS
  We retrospectively reviewed MR images of 30 patients with IP and 128 patients with various malignant sinonasal tumors proved on histologic examination and compared the prevalence of a CCP between the 2 groups. In 8 patients with IP concomitant with squamous cell carcinoma, we also tried to find the MR features to help suggest coexistent malignancy.
  
  
  RESULTS
  A CCP was demonstrated in all 30 (100%) of the IPs and 17 (13%) of the 128 malignant sinonasal tumors on MR imaging. There was a significant statistical difference in the prevalence of a CCP between IP and malignant sinonasal tumors with the overall sensitivity, specificity, positive predictive value, negative predictive value, and accuracy 100%, 87%, 64%, 100%, and 89%, respectively. Of 8 IPs concomitant with squamous cell carcinoma, a focal loss of a CCP was demonstrated in 4 tumors, 3 of which also showed aggressive bone destruction with extrasinonasal extension on MR images.
  
  
  CONCLUSIONS
  Although a CCP is a reliable MR imaging feature of sinonasal IPs, it can also be seen in various malignant sinonasal tumors. A focal loss of a CCP might be a clue to the diagnosis of IPs concomitant with malignancy.
authors.affiliation: Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: T Y
authors.initials: TY
authors.lastname: Jeon
authors.forename: H-J
authors.initials: HJ
authors.lastname: Kim
authors.forename: S-K
authors.initials: SK
authors.lastname: Chung
authors.forename: H-J
authors.initials: HJ
authors.lastname: Dhong
authors.forename: H Y
authors.initials: HY
authors.lastname: Kim
authors.forename: Y J
authors.initials: YJ
authors.lastname: Yim
authors.forename: S T
authors.initials: ST
authors.lastname: Kim
authors.forename: P
authors.initials: P
authors.lastname: Jeon
authors.forename: K H
authors.initials: KH
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018308:Papilloma, Inverted / Q000175:diagnosis*; D010255:Paranasal Sinus Neoplasms / Q000175:diagnosis*