Bilateral simultaneous sino-nasal inverted papilloma; A report of two cases and literature review.
INTRODUCTION
Inverted Papilloma is a benign sinonasal tumor with a high recurrence rate and potential for malignant transformation, it typically presents as an obstructing unilateral nasal mass, atypical presentations include bilateral involvement which occurs in up to 5 % of cases.


CASE PRESENTATION
Here we present two different cases of bilateral inverted papilloma, both presented complaining of bilateral nasal obstruction, the second case also had associated nasal polyposis and history of multiple previous endoscopic sinus surgeries, both cases were managed with endoscopic medial maxillectomy and tumor removal, with no signs of recurrence on follow up.


CONCLUSION
Bilateral involvement is an uncommon, atypical presentation of inverted papilloma, endoscopic surgery is a safe, reliable approach and it is the mainstay of treatment, regular endoscopic and clinical follow up is important for detection of recurrence.
['Al Momen|Ali|A|', 'Alenzi|Haifa Lafi|HL|', 'Al Eid|Mohammad|M|']
Inverted papilloma Nasal obstruction Endoscopic sinus surgery Nasal sinuses Nose