Ectopic pituitary adenoma of the third ventricle. Case report.

Ectopic pituitary adenomas without associated intrasellar adenomas are rare and are usually located in the sphenoid sinus. Most have been reported without modern radiological, endocrinological, or electron microscopic (EM) documentation. The case of a 47-year-old man with a third ventricular, ectopic, clinically nonsecretory pituitary adenoma, which was shown to be a gonadotrophic adenoma by immunohistochemical and EM study, is reported. Neurological examination, extensive neurodiagnostic imaging, surgical anatomical observation, and endocrinological evaluation showed no evidence of neoplasia outside the third ventricle.