Clinical characteristics and management of insulin-producing neuroendocrine carcinomas

Background and study aims: Due to rarity of insulin-producing pancreatic neuroendocrine carcinomas, no large, nor randomized studies of the clinical course, treatment options and outcome are available. Therefore, we want to share our personal experience and we retrospectively reviewed a cohort of five patients. Patients and methods: This study reports on the clinical characteristics, disease course, management and outcome of five patients with an advanced pancreatic neuroendocrine carcinoma with insulin production, which we followed recently in our center (between 2006 and 2015). Extraordinary for our cohort is that, except for one patient, which was diagnosed with a de novo malignant insulinoma, all other patients were diagnosed with a non-functional pancreatic neuroendocrine tumor which evolved during the disease course to a malignant insulinoma. Results: Although various treatment strategies, both surgical and medical, are used to prolong survival and prevent hypoglycemic events, long-term prognosis of these patients remains poor, especially after transformation of a non-functional pancreatic neuroendocrine tumor to an insulin-producing neuroendocrine carcinoma. Of all five patients, only one is still alive, the other four died 25, 17, 3 and 1 month(s) after diagnosis of the malignant insulinoma. In general, prognosis is determined by early diagnosis and treatment, and by resectability of the tumor and its biological behavior. Conclusions: Management of a malignant insulinoma is very challenging and a better understanding of the underlying mechanisms of this disease entity and its biological behavior is absolutely necessary to improve diagnostic tools, treatment and outcome in the future. (Acta gastroenterol. belg., 2016, 79, 321-327).