[Pseudo-pituitary tumor and hypopituitarism secondary to a sphenoid sinus inverted papilloma]

Inverted papilloma (IP) is a benign uncommon epithelial tumor, arising mostly from the lateral nasal wall. Though benign, this lesion is highly invasive into surrounding tissues and malignant transformation may occur. Primary IP of the sphenoid sinus and intracranial extension with dural invasion, even without histological evidence of malignancy, has only rarely been described. Hypopituitarism as a complication of this lesion has never been reported. We describe the case of a 59-year-old woman who was evaluated because of a 5-year-history of severe headaches and abnormalities in the visual field. Magnetic resonance imaging (MRI) showed a 1.4 per 2.0 cm heterogeneous sellar lesion with suprasellar and sphenoid sinus extension, eroding the sellar floor with optic chiasm compression. Otolaryngologists gave her 16 mg/day of prednisone during approximately 3 months with a near total regression of the mass on MRI. The endocrine biochemical evaluation showed pituitary gonadal, thyroid and adrenal insufficiency. A new MRI showed growth of the tumor with obliteration of the sphenoid sinus. An endoscopic sinus biopsy revealed an IP, so a transnasal endoscopic sinus surgery was performed with complete resection evidenced by MRI a year later.