title: Clinicopathological characteristics and prognosis of rectal well-differentiated neuroendocrine tumors.
abstract: BACKGROUND
  To clarify the oncological outcome of rectal well-differentiated neuroendocrine tumors (W/D NETs), we examined the clinicopathological characteristics and prognosis of patients with this neoplasm.
  
  
  METHODS
  A total of 23 patients who underwent surgical treatment with lymph node dissection for rectal W/D NETs between 1973 and 2007 were reviewed.
  
  
  RESULTS
  Median tumor size measured preoperatively was 13 mm (range, 4-25 mm), and the median number of dissected lymph nodes was 16 (range, 1-46). The incidence of lymph node metastasis was 61% (14 of 23 cases). The smallest W/D NETs with lymph node metastasis was 10 mm in diameter. All the patients without lymph node metastasis survived without recurrence. Among 11 patients who had only regional lymph node metastasis, only one developed liver metastasis and died 13 months after initial surgery. Among three patients with lateral pelvic lymph node metastasis, two survived more than 5 years, although two had liver metastasis.
  
  
  CONCLUSIONS
  Because the incidence of lymph node metastasis is very high in patients with rectal W/D NETs greater than 10 mm in diameter, radical surgery is required. In this series, the outcome of rectal W/D NETs patients with lateral pelvic lymph node metastasis was better than expected.
authors.affiliation: Department of Surgery, National Cancer Center Hospital, Shin Fujita, Tokyo, Japan.
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Tsukamoto
authors.forename: Shin
authors.initials: S
authors.lastname: Fujita
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Yamaguchi
authors.forename: Seiichiro
authors.initials: S
authors.lastname: Yamamoto
authors.forename: Takayuki
authors.initials: T
authors.lastname: Akasu
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Moriya
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Taniguchi
authors.forename: Tadakazu
authors.initials: T
authors.lastname: Shimoda
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000096:biosynthesis; D053379:Chromogranin A / Q000096:biosynthesis; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging / Q000379:methods; D018358:Neuroendocrine Tumors / Q000378:metabolism / Q000401:mortality / Q000473:pathology*; D011379:Prognosis; D012004:Rectal Neoplasms / Q000378:metabolism / Q000401:mortality / Q000473:pathology*; D012189:Retrospective Studies; D012720:Severity of Illness Index; D015996:Survival Rate; D016708:Synaptophysin / Q000096:biosynthesis
chemical_list: D014408:Biomarkers, Tumor; D053379:Chromogranin A; D016708:Synaptophysin