title: Neuroendocrine tumors of the gallbladder: twelve cases in a single institution.
abstract: OBJECTIVE
  We report a single center experience of 12 cases with neuroendocrine tumor (NET) of the gallbladder.
  
  
  METHODS
  Twelve patients were diagnosed with gallbladder NET between July 1998 and February 2008 and assessed according to the WHO histological classification. Six patients underwent surgical resection and 6 patients underwent nonsurgical treatment.
  
  
  RESULTS
  There was one well-differentiated neuroendocrine carcinoma (NEC), 6 poorly differentiated NECs, and 5 mixed exocrine-endocrine carcinomas. All poorly differentiated NECs were small cell carcinomas; four patients had distant metastases at the time of diagnosis; and underwent chemotherapy. All five patients with mixed exocrine-endocrine carcinomas underwent operative treatments. The group with mixed exocrine-endocrine carcinomas and the group with poorly differentiated NECs didn't show a significant difference in overall survival (9.3 months vs. 8.0 months, respectively; p = 0.997). A patient with well-differentiated NEC had portal vein invasion and underwent aggressive curative surgery, but liver metastasis occurred after 1 month and she survived for 9.9 months.
  
  
  CONCLUSIONS
  NECs of the gallbladder are very aggressive tumors showing poor survival outcomes against current treatments. Further understanding on the clinical and pathologic characteristics of these NETs seems to be necessary to find more effective treatment modalities.
authors.affiliation: Department of Surgery, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Jae-Myeong
authors.initials: JM
authors.lastname: Lee
authors.forename: Shin
authors.initials: S
authors.lastname: Hwang
authors.forename: Sung-Gyu
authors.initials: SG
authors.lastname: Lee
authors.forename: Young-Joo
authors.initials: YJ
authors.lastname: Lee
authors.forename: Kwang-Min
authors.initials: KM
authors.lastname: Park
authors.forename: Ki-Hun
authors.initials: KH
authors.lastname: Kim
authors.forename: Chul-Soo
authors.initials: CS
authors.lastname: Ahn
authors.forename: Myung-Hwan
authors.initials: MH
authors.lastname: Kim
authors.forename: Sung-Koo
authors.initials: SK
authors.lastname: Lee
authors.forename: Myung Wook
authors.initials: MW
authors.lastname: Kim
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019002:CD56 Antigen / Q000032:analysis; D002454:Cell Differentiation; D005260:Female; D005706:Gallbladder Neoplasms / Q000401:mortality / Q000473:pathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D018358:Neuroendocrine Tumors / Q000401:mortality / Q000473:pathology*
chemical_list: D019002:CD56 Antigen; C522918:NCAM1 protein, human