“…In up to 70% of cases, occult ectopic tumours may express and co-secrete one or more additional peptides such as calcitonin, somatostatin, gastrin, pancreatic polypeptide, vasoactive intestinal peptide, glucagon, human chorionic gonadotropin-β, α-fetoprotein, α-subunit, neuron-specific enolase, growth hormone releasing hormone, CRH and/or carcinoembryonic antigen [64, 65]. Thus, measurement of these specific peptides may sometimes be useful.…”