Unresectable giant pancreatic neuroendocrine tumor effectively treated by high-intensity focused ultrasound: a case report and review of the literature.

Patients with pancreatic neuroendocrine tumors (PNETs) diagnosed at late stage are not suitable candidates for surgery. So far, only a limited number of cases have been documented in literature about the effectiveness of HIFU, which has been more frequently reported to treat pancreatic adenocarcinoma rather than PNET. We report herein that a patient with a pancreatic neuroendocrine unresectable tumor was effectively treated with serial high-intensity focused ultrasound (HIFU) ablation, with no significant side effects detected. Upon evaluation, treatment results included: the tendency of tumor shrinkage, pain relief, decreased tumor marker levels, and obvious improvements in quality of life. Sustained efficacy was observed during a follow-up at 25 months with no tumor progression. Crown