Isolated oncocytic sinonasal papilloma of the sphenoidal sinus.

The ectodermally derived mucosa of the nose and paranasal sinuses may give rise to three morphologically different papillomas referred to individually as exophytic papilloma, inverted papilloma (IP) and oncocytic sinonasal papilloma (OSP). OSP is the rarest of the three different types, frequently affects the maxillary sinus, ethmoid sinus and nasal cavity while sphenoidal sinus involvement is exceedingly rare. The tumour has no gender predilection and has a wide age range with the majority above 50 years of age. Clinically, its behaviour parallels IP due to local recurrence and tendency to malignant transformation. Microscopically, the tumour shows multilayered eosinophilic epithelium with exophytic and inverted growth patterns. We report a case of OSP of the sphenoidal sinus, which, to the author's knowledge, is one of the few cases of isolated sphenoidal sinus OSP reported in the English literature. In this article, we describe how the patient presented, was diagnosed and how it was managed.