Ectopic Corticotropin-Releasing Hormone-Secreting Pancreatic Neuroendocrine Tumor: Excellent Response of Liver Metastases to Peptide Receptor Radionuclide Therapy as Demonstrated by 68Ga-DOTATOC and 18F-FDG PET/CT Imaging.

Ectopic Cushing syndrome secondary to corticotropin releasing hormone (CRH)-secreting tumors or CRH and adrenocorticotropin hormone cosecreting tumors is extremely rare. We report here the case of a 54-year-old man who experienced CRH-secreting pancreatic neuroendocrine tumor causing Cushing syndrome, initially detected by SSTR (somatostatin receptor) scintigraphy, then significantly progressed with multiple liver metastases, demonstrating significantly increased SSTR expression on Ga-DOTATOC PET/CT and a "mismatch" imaging pattern on F-FDG PET/CT. The patient underwent peptide receptor radionuclide therapy with Lu/Y-DOTATOC and demonstrated excellent response to the treatment.