Cystic pancreatic neuroendocrine tumors (cPNETs): a systematic review and meta-analysis of case series

Cystic pancreatic neuroendocrine tumors represent 13% of all neuroendocrine tumors. The aim of this study is to analyze the phenotype and biologic behavior of resected cystic neuroendocrine tumors. A systematic review and meta-analysis were conducted until September 2016 using a search in Medline, Scopus, and EMBASE with the terms "cystic pancreatic endocrine neoplasm", "cystic islets tumors" and "cystic islets neoplasms". From the 795 citations recovered 80 studies reporting on 431 patients were selected. 87.1% (n = 387) were sporadic tumors and 10.3% (n = 40) corresponded to multiple endocrine neoplasia endocrine type 1. Were diagnosed incidentally 44.6% (n = 135). Cytology was found to have a sensitivity of 78.5%. Were non-functional tumors 85% (n = 338), and among the functional tumors, insulinoma was the most frequent. According to the European Neuroendocrine Tumor Society staging, 87.8% were limited to the pancreas (I-IIb), and 12.2% were advanced (III-IV). Disease-free survival at 5 years in stages (I-IIIa) and (IIIb-IV) was 91.5% and 54.2%, respectively; and was significantly lower (p = 0.0001) in functional tumors. In patients with multiple endocrine neoplasia there was a higher incidence of functional (62.5%) and multifocal (28.1%) tumors. Disease-free survival at 5 and 10 years was 60%. Cystic pancreatic neuroendocrine tumors exhibit phenotypical characteristics which are different to those of solid neuroendocrine tumors.

Non-secreting benign glucagonoma diagnosed incidentally in a patient with refractory thrombocytopenic thrombotic purpura: report of a case

Thrombotic thrombocytopenic purpura (TTP) is a rare hematologic disorder, which may be idiopathic or secondary to a variety of diseases. However, there are very few reports of TTP in the context of pancreatic neoplasms. We report a case of relapsing TTP after initial treatment with plasmapheresis, corticosteroids, and rituximab, in a 59-year-old woman. During diagnostic work-up, a pancreatic lesion 35 × 25 mm in size was discovered incidentally and splenopancreatectomy was performed. The pathological diagnosis was benign glucagonoma. The hematological symptoms resolved completely after the procedure and 3 years later, the patient is well with no sign of recurrence of TTP or glucagonoma. To our knowledge, this represents the first documented case of a non-secreting benign pancreatic neuroendocrine tumor (glucagonoma) associated with TTP that is refractory to standard treatment.