Inverted papilloma of the sphenoid sinus: presentation of three cases

INTRODUCTION: Inverted papilloma deriving originally from the sphenoid sinus is extremely rare. Three such cases are presented aiming to show the particularities and diagnostic clues of this clinical entity. CASE REPORTS: All three patients were male, and presented mainly with nasal symptoms. In all three cases imaging shows the sphenoid sinus was completely occupied by the tumor. Additionally the ethmoids and nasal cavities have been invaded in contiguity to the site of the initial appearance of the tumor. In particular one of the cases was of even more interest as a malignant transformation of the inverted papilloma of the sphenoid sinus was histologically observed. Endoscopic sinus surgery was the therapeutic approach chosen for all three cases, with very good results. Follow up 30 months after the operation has not revealed any signs of recurrence of the disease. CONCLUSION: Inverted papilloma of the sphenoid sinuses--and even more malignant transformation--although quite rare, may present occasionally. The ENT surgeon should be aware of this condition. Preoperative imaging with CT scan and MRI and the experience of the surgeon will dictate the appropriate surgical approach.