title: Mesorectal spread and micrometastasis of rectal cancer studied with large slice technique and tissue microarray.
abstract: OBJECTIVE
  Mesorectal tissue seems to be an ideal substrate for the spreading of tumors. The aim was to study the distribution of mesorectal neoplastic foci, examine occurrence of circumferential margin involvement and investigate micrometastasis of the lymph nodes.
  
  
  METHODS
  A large slice technique, combined with tissue microarray, was used in the pathologic study of 31 specimens operated on following the principles of total mesorectal excision (TME).
  
  
  RESULTS
  Three hundred and forty-nine mesorectal neoplastic foci were examined from 18 specimens. Almost one third of them were in the outer layer of mesorectum. Concerning position of primary tumor, ipsolateral neoplastic foci were significantly more than contralateral neoplstic foci. Twelve specimens were diagnosed to have circumferential margin involved. Nine hundred and ninety-two lymph nodes were harvested with 148 involved by tumor. No significant difference in occurrence of micrometastasis was observed among tumors of different stage.
  
  
  CONCLUSIONS
  Combination of large slice and tissue microarray provided a more detailed method in studying the spread of rectal cancer. Complete excision of the mesorectum with fascia propria circumferentially intact is essential since there is an outer scattering and lateral discrepancy for neoplastic foci distribution. Circumferential margin involvement and micrometastasis observed suggested adoption of preoperative and/or postoperative radiochemotherapy.
authors.affiliation: Department of General Surgery, West China Hospital, Sichuan University, Chengdu, PRChina.
authors.forename: Cun
authors.initials: C
authors.lastname: Wang
authors.forename: Zong-Guang
authors.initials: ZG
authors.lastname: Zhou
authors.forename: Zhao
authors.initials: Z
authors.lastname: Wang
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.forename: Yang-Chun
authors.initials: YC
authors.lastname: Zheng
authors.forename: Gao-Ping
authors.initials: GP
authors.lastname: Zhao
authors.forename: Dai-Yun
authors.initials: DY
authors.lastname: Chen
authors.forename: Wei-Ping
authors.initials: WP
authors.lastname: Liu
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D016591:Histocytological Preparation Techniques; D006801:Humans; D016015:Logistic Models; D008207:Lymphatic Metastasis / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness / Q000473:pathology; D009364:Neoplasm Recurrence, Local / Q000517:prevention & control; D012004:Rectal Neoplasms / Q000473:pathology* / Q000601:surgery; D046888:Tissue Array Analysis