Ectopic adrenocorticotropin production: disappearance after removal of inflammatory tissue

A patient presented with the clinical and laboratory features of the ectopic ACTH syndrome. No ACTH-producing tumor was found, and bilateral adrenalectomy was performed to correct the hypercortisolism. Six months later, the removal of a pseudotumor containing only fat and inflammatory tissue resulted in normalization of both basal plasma ACTH levels and the ACTH feedback response to cortisol infusion. It is suggested that the leukocytes in the inflammatory tissue were the source of the ectopic ACTH production.