ACTH-producing tumor

ACTH-producing pancreatic neuroendocrine tumors (PanNETs) are rare neoplasms, accounting for a minority of all PanNETs. Nevertheless, they are one of the leading non-pulmonary causes of the so-called ectopic ACTH-dependent Cushing's syndrome (ECS). The first ECS-associated PanNET was described in 1950 by Del Castillo and coworkers. Since then, less than 150 cases have been reported in the English literature The diagnosis of ACTH-producing PanNETs may be a clinical challenge, in particular when the presentation of the Cushing’s syndrome is not typical. The milestones of the diagnosis are the detection of high circulating levels of ACTH and cortisol and the discovery of a pancreatic mass. ACTH-producing PanNETs have a female predominance, and the age of the patients is somewhat younger than in other PanNETs. Morphologically, they show the features of well-differentiated neuroendocrine tumors, but they are often larger than other PanNETs and frequently metastatic at the time of the diagnosis. Immunohistochemical staining helps to define the corticotroph phenotype of tumor cells.The prognosis of these tumors is often poor, with patients dying in a few months or years with metastatic disease.