title: EUS-FNA assessment of extramesenteric lymph node status in primary rectal cancer.
abstract: BACKGROUND
  Preoperative staging is an essential factor in the multidisciplinary management of rectal cancer. The accuracy of imaging alone with CT, magnetic resonance imaging, or rigid endorectal US is poor. The addition of EUS-FNA may enhance extramesenteric lymph node metastases detection (M1 disease) and overall staging accuracy.
  
  
  OBJECTIVE
  To evaluate the frequency of extramesenteric lymph node visualization by EUS and the rate of extramesenteric lymph node metastases by FNA. Secondary goals were to evaluate the clinical, endoscopic, and sonographic features associated with extramesenteric lymph node metastases, disease progression, and overall mortality.
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  Tertiary referral center.
  
  
  RESULTS
  Forty-one of 316 patients (13%) with primary rectal cancer over a 6-year period had M1 disease by EUS-FNA. Significant clinical, endoscopic, and sonographic features associated with extramesenteric lymph node metastases included the serum carcinoembryonic antigen level, tumor length 4 cm and longer, annularity 50% or more, sessile morphology, and lymph node size. The sensitivity and specificity of CT for extramesenteric lymph node metastases were 44% and 89%, respectively. Twenty-three of 316 rectal cancer endosonographic procedures (7.3%) were up-staged by FNA, which established extramesenteric lymph node metastases. Over a 4-year follow-up, disease progression and overall mortality of patients with extramesenteric lymph node metastases was observed in 6 patients (14.6%) and 14 patients (34%), respectively.
  
  
  CONCLUSIONS
  Preoperative EUS-FNA identification of extramesenteric lymph node metastases outside of standard radiation fields or total mesorectal excision resection margins could affect medical and surgical planning.
authors.affiliation: Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, Rochester, MN, USA.
authors.forename: Ferga C
authors.initials: FC
authors.lastname: Gleeson
authors.forename: Jonathan E
authors.initials: JE
authors.lastname: Clain
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Rajan
authors.forename: Mark D
authors.initials: MD
authors.lastname: Topazian
authors.forename: Kenneth K
authors.initials: KK
authors.lastname: Wang
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Levy
mesh_terms: D044963:Biopsy, Fine-Needle; D018450:Disease Progression; D019160:Endosonography; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000000981:diagnostic imaging / Q000473:pathology*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012004:Rectal Neoplasms / Q000401:mortality / Q000473:pathology*; D012680:Sensitivity and Specificity; D015996:Survival Rate; D014057:Tomography, X-Ray Computed