%0 Journal Article %A T.Y. Jeon %A H.-J. Kim %A S.-K. Chung %A H.-J. Dhong %A H.Y. Kim %A Y.J. Yim %A S.T. Kim %A P. Jeon %A K.H. Kim %T Sinonasal Inverted Papilloma: Value of Convoluted Cerebriform Pattern on MR Imaging %D 2008 %R 10.3174/ajnr.A1128 %J American Journal of Neuroradiology %P 1556-1560 %V 29 %N 8 %X BACKGROUND AND PURPOSE: 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.MATERIALS AND 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.CONCLUSION: 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. %U https://www.ajnr.org/content/ajnr/29/8/1556.full.pdf