Inverted papilloma is a benign tumor of upper respiratory epithelium that is slow growing but has a propensity for local invasion and recurrence. It not only can involve the nose and paranasal sinuses, but it also can extend into the orbit, nasolacrimal duct, pterygoid fossa, and anterior cranial fossa. Bone invasion can occur with both benign tumors and tumors that have undergone malignant transformation. We describe the first reported case (to our knowledge) of an inverted papilloma with benign and malignant elements that extended by perineural spread to cause bilateral cavernous sinus invasion. Furthermore, retrograde extension to Meckel cave developed bilaterally, with perineural spread along the third division of the trigeminal nerve into the masticator space and the skull base.
Lin FY, Park CW, Som P, Lawson W. Bilateral Cavernous Sinus Involvement by Perineural Spread of Inverted Papilloma. Arch Otolaryngol Head Neck Surg. 2010;136(9):920-922. doi:10.1001/archoto.2010.144