As expected, most frequently encountered tumors with ectopic ACTH secretion were of pulmonary origin (bronchus carcinoid, pulmonary/small cell lung carcinoma), others included thymic (thymoma/thymic carcinoma), gastro-intestinal (insulinoma, gastrinoma, somatostatinoma, gastric NEC, small bowel carcinoma NET, and carcinoma), pancreatic NET, medullary thyroid carcinoid, olfactory neuroblastoma, and metastatic foci of unknown origin. Here, POMC is linked to gastrin-producing neuroendocrine tumor.