Ectopic Cushing's Syndrome Due to Pancreatic Neuroendocrine Tumor: A Rarely Case Report

Both a non-functional neuroendocrine tumor that transforms into an ACTH-secreting tumor and ectopic ACTH-secreting Cushing's disease are extremely uncommon. We present the case of a 75-year-old female patient who underwent total surgery for a pancreatic neuroendocrine tumor that was discovered 11 years prior and was non-functional at the time of diagnosis. Five years ago, liver metastases were found, and they currently exhibit Cushing's syndrome symptoms that depend on ACTH. A presumptive diagnosis of a rapidly progressive, metastatic, functional pancreatic neuroendocrine tumor with ectopic ACTH secretion was made and biochemically and radiographically confirmed. However, due to health conditions and procedural risks, definite diagnostic methods have not been developed, such as liver biopsy. Conclusion: This report highlights the fact that it is unlikely that a neuroendocrine tumor of the pancreas may initially present with a functional hormonal syndrome, either from the primary tumor itself or from the metastatic secondary tumor.