title: Implications of incidentally discovered, nonfunctioning pancreatic endocrine tumors: short-term and long-term patient outcomes.
abstract: OBJECTIVE
  To describe the characteristics and outcomes after resection of incidentally discovered, nonfunctioning pancreatic endocrine tumors (PETs).
  
  
  METHODS
  Case series.
  
  
  METHODS
  Academic hospital.
  
  
  METHODS
  Consecutive patients with an incidentally identified, nonfunctioning PET resected from May 1, 1977, through July 31, 2009.
  
  
  METHODS
  Operative morbidity and survival after resection.
  
  
  RESULTS
  A total of 139 patients with median age of 56 years (range, 21-85 years) underwent resection; tumor size ranged from 0.4 to 17.0 cm, with median size of 3.0 cm. No perioperative deaths were reported. Sixty-one patients (43.9%) experienced a perioperative complication. Twenty-six tumors (18.7%) were classified as benign, 39 (28.1%) as malignant, and 72 (51.8%) as uncertain. We were unable to confidently classify 2 tumors due to lack of information regarding mitotic rate in the pathology report. Complete follow-up was available for 112 patients (80.6%) (median, 34.2 months). Five-year actuarial survival rates were 88.8% for patients with benign disease, 92.5% for patients with tumors of uncertain biology, and 49.8% for those with malignant tumors (P = .01). Late metastasis, tumor recurrence, or disease progression were seen in 1 patient (3.8%) with tumors initially classified as benign, 8 patients (11.1%) with uncertain tumors, and 15 patients (38.5%) with tumors classified as malignant (P < .001). Of the 39 patients with tumors 2 cm or smaller, 3 (7.7%) had late metastases or recurrence. When compared with patients with symptomatic, nonfunctioning PETs, no large difference was observed in tumor size, patient age, disease, or survival.
  
  
  CONCLUSIONS
  Incidentally detected, nonfunctioning PETs can display aggressive behavior, even when small. Although patients with malignant disease had diminished survival and increased rates of recurrence, benign histologic findings did not eliminate the possibility of progression. Patients with incidentally discovered, nonfunctioning PETs should undergo tumor resection and careful postoperative surveillance, even if surgical pathologic findings suggest benign disease.
authors.affiliation: Department of Surgery, Massachusetts General Hospital, Wang Ambulatory Care Center 460, 15 Parkman St, Boston, MA 02114, USA. cfernandez@partners.org
authors.forename: Alex B
authors.initials: AB
authors.lastname: Haynes
authors.forename: Vikram
authors.initials: V
authors.lastname: Deshpande
authors.forename: Thun
authors.initials: T
authors.lastname: Ingkakul
authors.forename: Parsia A
authors.initials: PA
authors.lastname: Vagefi
authors.forename: Jackie
authors.initials: J
authors.lastname: Szymonifka
authors.forename: Sarah P
authors.initials: SP
authors.lastname: Thayer
authors.forename: Cristina R
authors.initials: CR
authors.lastname: Ferrone
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Wargo
authors.forename: Andrew L
authors.initials: AL
authors.lastname: Warshaw
authors.forename: Carlos
authors.initials: C
authors.lastname: Fernández-del Castillo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D006498:Hepatectomy; D006801:Humans; D033162:Incidental Findings; D053208:Kaplan-Meier Estimate; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D018358:Neuroendocrine Tumors / Q000175:diagnosis / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D010179:Pancreas / Q000473:pathology; D010180:Pancreatectomy; D010190:Pancreatic Neoplasms / Q000175:diagnosis / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D016577:Pancreaticoduodenectomy; D011183:Postoperative Complications / Q000175:diagnosis / Q000401:mortality; D012189:Retrospective Studies; D047368:Tumor Burden; D055815:Young Adult