Ectopic prolactinoma in a patient with hyperparathyroidism and abnormal sellar radiography.

In a patient with hyperparathyroidism and chronic renal failure due to polycystic kidney disease, a finding of destroyed sellar and parasellar structures and hyperprolactinemia suggested the diagnosis of invasive pituitary prolactinoma. At surgery no tumor was found, and pathological examination of the sphenoid bone revealed a parathyroid bone lesion (brown tumor) as well as ectopic prolactinoma in the clivus. This patient demonstrates that a tumor may develop in ectopic pituitary tissue. The combination of radiographically abnormal sellar structures with pituitary hormone hypersecretion should not be regarded as absolute proof of a pituitary adenoma.