Inverted papilloma invading the orbit.

Inverted papilloma is an unusual entity for many ophthalmologists. We report a case of inverted papilloma of the nasal cavity and sinuses, invading the orbit in a 33-year-old man. The patient presented with a right medial canthal mass, proptosis, diminution of vision, epiphora and nasal obstruction. In the past, he underwent multiple procedures for surgical removal of the tumor with frequent recurrences. A computed tomographic scan revealed a mass filling both the nasal cavities and sinuses, destroying adjacent bones and invading the medial aspect of the orbit, leading to proptosis. Excision of the tumor was performed by a lateral rhinotomy approach. The tumor proved to be an inverted papilloma with focal transformation to transitional cell carcinoma. Post-operative CT scan revealed residual tumor, which responded to radiotherapy, with no recurrence over six months. Histopathologically, these tumors are benign, but locally invasive. The tumors that invade the orbit are usually locally aggressive, highly malignant and recur frequently. Radical excision of the tumor is technically difficult and often incomplete, so radiotherapy should be considered as an adjunct to surgery.