Objective: The objective of this study is to describe potentially distinctive MR features of sinonasal inverted papilloma and those of coexisting squamous cell carcinoma.
Conclusion: A sinonasal mass with a convoluted cerebriform pattern on T2- or enhanced T1-weighted images suggests inverted papilloma as a histologic diagnosis. Necrosis in a mass with such an appearance strongly suggests coexistent carcinoma.