RESUMO
Inverted papilloma is a tumor found involving the nasal cavity and paranasal sinuses. They are not cancerous but can be locally aggressive. They are most commonly seen involving the lateral wall of nose and maxillary sinus. When the tumor involves the frontal sinus and sphenoid sinus or the post ethmoid cells it presents a surgical challenge. Inverted papilloma almost always occur unilateraly and affect mainly the maxillary sinus. Inverted papilloma arising from the sphenoid and frontal sinuses are rare. Here we present two cases; one involving a 60 year man, with inverted papilloma originating from the frontal sinus and another case where it originated from the sphenoid sinus anterior wall and posterior ethmoidalcell (Onodi cell) and was resected endoscopically.
