title: Left-right asymmetry in pelvic lymph nodes distribution: is there a right-side prevalence?
abstract: OBJECTIVE
  To assess whether pelvic lymph nodes have a left-right asymmetric distribution.
  
  
  METHODS
  The oncologic databases of two gynecologic academic departments were used to identify consecutive patients undergoing pelvic systematic lymphadenectomy as part of the treatment for a variety of gynecologic malignancies. All procedures were carried out in a standardized fashion. Lymph node counts were retrieved from pathological reports.
  
  
  RESULTS
  Four hundred and twenty-eight women underwent pelvic lymphadenectomy during the study period. The median lymph node count was higher on the right side than on the left side [10 (0-33) versus 8 (0-29); P<0.0001]. A prevalence of right-sided nodes was found in 265 (61.9%) patients, while in 44 (10.3%) cases pelvic nodes were equally distributed on the two sides. The right-sided prevalence was significantly higher than the expected 50% in each type of malignancy and surgical technique subgroup. The right-sided prevalence was statistically significant even when the analysis was performed for different nodal groups [external iliac nodes: 5 (0-23) versus 4 (0-13), P=0.005; hypogastric and obturator nodes: 6 (0-17) versus 5 (0-19), P=0.04]. Moreover, nodal count was higher on the right than on the left in obese [10 (1-33) versus 8 (1-26), P=0.0002] and nonobese women [10 (0-32) versus 9 (0-29), P<0.0001].
  
  
  CONCLUSIONS
  Our findings suggest the existence of a left-right asymmetry in pelvic lymph nodes distribution, with right-sided prevalence.
authors.affiliation: Department of Obstetrics and Gynecology, University of Insubria, Varese, Italy. fabio.ghezzi@uninsubria.it
authors.forename: Fabio
authors.initials: F
authors.lastname: Ghezzi
authors.forename: Antonella
authors.initials: A
authors.lastname: Cromi
authors.forename: Stefano
authors.initials: S
authors.lastname: Uccella
authors.forename: Silvia
authors.initials: S
authors.lastname: Giudici
authors.forename: Massimo
authors.initials: M
authors.lastname: Franchi
authors.forename: Pierfrancesco
authors.initials: P
authors.lastname: Bolis
mesh_terms: D016889:Endometrial Neoplasms / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D010535:Laparoscopy; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000033:anatomy & histology / Q000473:pathology* / Q000601:surgery*; D009765:Obesity / Q000150:complications* / Q000473:pathology; D010051:Ovarian Neoplasms / Q000473:pathology* / Q000601:surgery; D010388:Pelvis; D011237:Predictive Value of Tests; D015995:Prevalence; D012307:Risk Factors; D002583:Uterine Cervical Neoplasms / Q000473:pathology* / Q000601:surgery