Cushing's disease due to double pituitary ACTH-secreting adenomas: the first case report.

Double pituitary adenomas are rare occurrences in autoptical, surgical and neuroradiological series and are mostly due to non-functioning pituitary adenomas, GH-secreting and prolactin-secreting adenomas. ACTH secreting tumours are more rare and, to our knowledge, two distinct ACTH-producing adenomas within the same pituitary have never been reported. We herewith describe a 56 year old woman with Cushing' s disease due to two clearly distinct ACTH-secreting pituitary adenomas. She presented with signs and symptoms of hypercortisolism and hormonal testing was indicative for pituitary-dependent Cushing' s syndrome. Sellar MRI visualized an asymmetric pituitary gland with suspect lesions in both the right and the left pituitary lobes. Both lesions were removed during transsphenoidal surgery and remission of hypercortisolism ensued. Pathology confirmed the existence of two distinct adenomas located in different sites in the gland. Both presented ACTH immunoreactivity but displayed distinct morphological features. Our case indicates that double ACTH-secreting pituitary adenomas may occur in patients with Cushing' s disease. Careful radiological, surgical and pathological examination is necessary to recognize this condition and avoid surgical failure.