RT Book, Section A1 Goff, Stephanie L. A1 Hughes, Marybeth S. A2 Morita, Shane Y. A2 Balch, Charles M. A2 Klimberg, V. Suzanne A2 Pawlik, Timothy M. A2 Posner, Mitchell C. A2 Tanabe, Kenneth K. SR Print(0) ID 1145758546 T1 Ectopic ACTH Syndrome T2 Textbook of Complex General Surgical Oncology YR 2018 FD 2018 PB McGraw-Hill Education PP New York, NY SN 9780071793315 LK hemonc.mhmedical.com/content.aspx?aid=1145758546 RD 2024/04/19 AB Cushing’s syndrome is a symptomatic manifestation of a wide variety of disease processes culminating in hypercortisolism, only a few of which, including ectopic ACTH syndrome (EAS), necessitate the attention of a surgical oncologist.1 In the classical setting of EAS, the diagnosis begins under the supervision of an endocrinologist, and the careful application of a diagnostic algorithm of laboratory testing, imaging, and/or interventional procedures often helps identify a source.2 However, EAS can also present in a paraneoplastic fashion in a patient with a known malignancy, and surgical oncologists may be called upon to identify a potential source. This chapter will briefly review the physiology of the hypothalamic-pituitary-adrenal (HPA) axis and Cushing’s syndrome, discuss the diagnosis of EAS and its descriptive classifiers, and outline management strategies for the care of patients with EAS.