Bilateral Sinonasal Inverted Papilloma: Report of an Uncommon Case Involving Sinuses of the Face and Orbital Cavity.

BACKGROUND Nasosinusal papilloma is a benign aggressive tumor. It usually occurs unilaterally in the nasal cavity and can extend to the sinuses. The diagnosis is made by the correlation of findings observed in tomographic and histopathological exams. The recommended treatment is surgical excision with clinical monitoring. Orbital involvement occurs in about 9% of cases of advanced SIP. However, there is no report of cases of a benign tumor that invaded the adjacent soft tissues. Therefore, our objective is to report an unusual case of SIP that bilaterally involved the nasal cavity and maxillary sinuses, and extended to involve the ethmoidal cells and sphenoid and frontal sinuses. CASE REPORT In this article, we report an unusual presentation of sinonasal inverted papilloma (SIP) in a 60-year-old man. The tumor bilaterally involved the nasal cavity and maxillary sinuses and extended to involve the ethmoidal cells and the sphenoid and frontal sinuses, as well as the orbital cavity on the right side. An open surgical procedure was performed for complete removal of the lesion and follow-up with imaging exams. CONCLUSIONS The involvement of these structures is uncommon in SIP. This highlights the importance of this case report. Diagnosis and surgical treatment must be carefully planned. In this work, we describe all the steps that helped guide the choice of the best surgical technique to be performed and offer the best clinical follow-up.