title: Pancreatic cystic endocrine tumors: a different morphological entity associated with a less aggressive behavior.
abstract: BACKGROUND
  Cystic pancreatic endocrine tumors (CPETs) are rare lesions and their biological features have been scarcely investigated.
  
  
  OBJECTIVE
  To compare clinical and pathological features of resected non-functioning sporadic CPETs (NF-CPETs) with solid pancreatic endocrine tumors (SPETs) in a single-institution experience.
  
  
  METHODS
  All patients with a pathologically confirmed diagnosis of sporadic non-functioning pancreatic endocrine tumors who underwent curative resection between 1990 and 2008 were included. A comparison of demographic, clinical and pathological characteristics between CPETs and SPETs was made. Univariate and multivariable analyses were performed to identify preoperative predictors of carcinoma (non-functioning pancreatic endocrine carcinoma).
  
  
  RESULTS
  Twenty-one (11.5%) patients with a histological diagnosis of NF-CPET were identified. The median age was 60 years (IQR 46.5-73.5 years) and a diagnosis of carcinoma (non-functioning pancreatic endocrine carcinoma) was made in 3 (14.3%) cases. In the comparison with NF-SPETs, no differences were found in terms of gender (p = 0.75), age (p = 0.81), presenting symptoms (p = 0.43), localization of the tumors (p = 0.46) and type of resection (p = 0.31). The incidence of non-functioning pancreatic endocrine carcinoma was significantly lower in the NF-CPET versus the NF-SPET group (14.3 vs. 40.4%, p = 0.04). By univariate analysis, preoperative predictors of non-functioning pancreatic endocrine carcinoma included the presence of symptoms (OR 3.96, 95% CI 2.06-7.63) and an increase in the absolute value of radiological diameter (OR 1.05, 95% CI 1.03-1.07). A cystic morphology of the lesion turned out to be a negative predictor of carcinoma (OR 0.25, 95% CI 0.70-0.87). These results were confirmed by multivariable analysis.
  
  
  CONCLUSIONS
  NF-CPETs have a measurable propensity to be benign. In those patients affected by small and asymptomatic NF-CPET a more conservative surgical approach or a follow-up policy could be considered.
authors.affiliation: Department of Surgery, S. Cuore-Don Calabria Hospital, Negrar, Italy.
authors.forename: Letizia
authors.initials: L
authors.lastname: Boninsegna
authors.forename: Stefano
authors.initials: S
authors.lastname: Partelli
authors.forename: Maria Michela
authors.initials: MM
authors.lastname: D'Innocenzio
authors.forename: Paola
authors.initials: P
authors.lastname: Capelli
authors.forename: Aldo
authors.initials: A
authors.lastname: Scarpa
authors.forename: Claudio
authors.initials: C
authors.lastname: Bassi
authors.forename: Paolo
authors.initials: P
authors.lastname: Pederzoli
authors.forename: Massimo
authors.initials: M
authors.lastname: Falconi
mesh_terms: D000328:Adult; D000368:Aged; D018278:Carcinoma, Neuroendocrine / Q000175:diagnosis* / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D015331:Cohort Studies; D003937:Diagnosis, Differential; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009361:Neoplasm Invasiveness; D010180:Pancreatectomy / Q000379:methods; D010181:Pancreatic Cyst / Q000175:diagnosis / Q000473:pathology; D010190:Pancreatic Neoplasms / Q000175:diagnosis* / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D016019:Survival Analysis