Supra- and extrasellar pituitary microadenoma as a cause of Cushing's disease

There has been accumulating evidence that pituitary adenomas which cause Cushing's disease are located not only in sella turcica but also in various extrasellar and intracranial regions. We describe a case of Cushing's disease caused by a supra- and extrasellar ACTH-producing microadenoma, which originated in the anterior pituitary and extended upward without connecting to the stalk. The pituitary microadenoma was identified and removed by transsphenoidal microsurgery. After the surgery the patient experienced complete remission. This type of pituitary microadenoma is considered to be rare, but in order to accomplish successful surgical treatment, it is necessary to consider that pituitary adenomas which cause Cushing's disease may be located in such an unusual position.