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60-Year-Old with Incidentally Found Sphenoid Sinus Lesion on CT
This case features a 60-year-old presenting with an incidentally found sphenoid sinus lesion on CT, ultimately diagnosed as an inverted papilloma.
Imaging overview:
Axial non-contrast CT in bone window demonstrates focal hyperostosis of the sphenoid sinus wall, marking the tumor origin. Axial T2 fat-saturated MRI and coronal T1 post-contrast MRI show an enhancing cerebriform polyploid mass extending into the nasopharynx, with the convoluted cerebriform pattern characteristic of inverted papilloma.
Clinical insight:
Inverted papilloma is a benign but locally aggressive epithelial tumor of the sinonasal tract with a high rate of recurrence and a small risk of malignant transformation. The convoluted cerebriform pattern on MRI is highly sensitive for the diagnosis and reflects the characteristic endophytic growth of the tumor. Focal hyperostosis on CT at the site of attachment is a useful imaging marker for identifying the tumor origin, which is important for surgical planning. While inverted papilloma most commonly arises from the lateral nasal wall or maxillary sinus, sphenoid sinus origin is uncommon and can present as an incidental finding, as in this case.
Case courtesy of Rebecca L. Kalik, BS, Robert A. Koenigsberg, MD, and Neelu Jain, MD, Temple University Hospital, Lewis Katz School of Medicine, Temple University.