We hereby describe a patient with cyclical Cushing’s syndrome due to ectopic production of adrenocorticotropic hormone (ACTH) by a bronchial carcinoid tumor, accurately diagnosed and treated within a short period of time. In addition we describe for the first time careful assessment of cortisol levels in the postoperative period without hormone replacement demonstrating limited need for steroid replacement. A 43-year-old female patient was referred for evaluation of Cushing’s syndrome. The diagnosis was made 2 months prior, because of the symptoms and elevated serum cortisol and urine free cortisol after a dexamethasone suppression test. Her symptoms improved and results of our laboratory studies were normal. Two months later symptoms developed again with elevated urine free cortisol and a paradoxical response to low and high-dose dexamethasone suppression test. The corticotrophin releasing hormone test suggested a nonpituitary origin. Magnetic resonance imaging of the pituitary was negative. Computed tomography and magnetic resonance imaging of the chest revealed a nodule in the right lung. Octreotide scan showed increased uptake in that area. She had a right lobectomy. Pathology revealed carcinoid tumor with ACTH staining. The cortisol levels were reduced, but steroid supplementation was not required for 2 weeks, supporting the cyclical nature of disease. This is a rare case of cyclical CS due to a bronchial carcinoid. High index of clinical suspicion and careful repeated laboratory evaluation over time is required to establish the diagnosis. Careful postoperative monitoring of cortisol values is needed. After resection of the ectopic source of ACTH, steroid supplementation may not always be needed.
*Professor of Medicine, Division of Endocrinology, Department of Medicine University of Arkansas for Medical Sciences; †Staff Physician, Central Arkansas Veterans Healthcare System, Little Rock, Arkansas; and ‡Physician, Little Rock Diagnostic Clinic, Little Rock, Arkansas.
The authors have disclosed that they have no significant relationships with or financial interests in any commercial organizations pertaining to this educational activity.
All staff in a position to control the content of this CME activity have disclosed that they have no financial relationships with, or financial interests in, any commercial companies pertaining to this educational activity.
Lippincott CME Institute has identified and resolved all faculty and staff conflicts of interest regarding this educational activity.
Reprints: Fred H. Faas, MD, 4301 W Markham Slot 587 Little Rock, AR 72205. E-mail: FaasFredH@uams.edu.
Chief Editor’s Note: This article is the 6th of 18 that will be published in 2008 for which a total of up to 18 AMA PRA Category 1 Credits™ can be earned. Instructions for how credits can be earned precede the CME Examination at the back of this issue.