If the diagnosis of Cushing’s disease is excluded after BIPSS, the next step is to perform a CT scan or MRI of the neck, thorax, abdomen and pelvis to identify the non-pituitary ACTH-producing tumor [14, 15]; however, it has been described that in up to 20 % of patients the site of ectopic ACTH secretion cannot be identified. This evidence concerns the gene POMC and neoplasm.