Vipoma/diarrheogenic syndrome: a statistical evaluation of 241 reported cases.

Based on a statistically reliable number of cases reported in international literature, this study aimed to analyze the present status of vipoma/diarrheogenic syndrome (DGS). Another purpose was to supply investigators in the field of pancreatic endocrinology with precise and extensive information for the future analysis and evaluation of this subject and related problems. We obtained a total of 241 patients with vipoma/DGS from the international literature of 179 with intrapancreatic vipomas, 48 with extrapancreatic neurogenic tumors such as ganglioneuroblastomas, ganglioneuromas and neuroblastomas, and 14 with extrapancreatic vipomas of non-neurogenic nature. When data were considered adequate, a comparative study was attempted between the two groups. A statistically significant difference between the two groups with pancreatic vipomas and neurogenic tumors was found in the rate of the associated syndrome (84.4% versus 95.8%: averaging 86.3%), in tumors the size of which was over 20 mm (79.1% versus 100.0%), in the metastases (56.4% versus 29.2%) and rate of malignancy (64.8% versus 33.3%), and in the rate of resection of primary lesions (68.7% versus 87.5%). When compared to nodal metastasis, hepatic involvement was significantly more frequent in the pancreatic vipoma group (4.2% versus 20.8%). Recent trials of adjuvant chemotherapy with somatostatin analogues indicates an effective result of 78.4% exceeding 31.0% when treated with streptozotocin. The 5-year survival rate in 89 effective patients with pancreatic vipomas was 68.5%; 59.6% for 43 of the patients with metastases and 94.4% for 46 of the patients without metastases.