POMC and neoplasm: Ectopic syndrome related to an ACTH-secreting tumor represents 12% to 17% of Cushing’s syndrome cases.[8] Ectopic ACTH production is mainly associated with small-cell carcinoma of the lung, but can also be found in various neuroendocrine tumors, such as bronchial, thymic, or pancreatic carcinoid, medullary carcinoma of the thyroid and pheochromocytoma.