Ectopic pituitary adenoma in the spheno-orbital region.

Ectopic pituitary adenomas (EPAs) are rare tumors that most often occur in the sphenoid sinus or suprasellar region. We describe a 66-year-old man who presented with unilateral proptosis and an ipsilateral abduction deficit caused by an EPA in the spheno-orbital region. The tumor was completely excised with elimination of proptosis and restoration of full ocular ductions. There were no complications. Diagnosis of a hormonally inactive EPA was reached on the basis of immunohistochemical studies of the operative specimen. This is the first documented case of an EPA in this location. It may have originated from Rathke pouch remnant cells in the lateral wall of the sphenoid sinus.