title: The Value of Mitotic Count and Ki67 Proliferation Index in Congenital Mesoblastic Nephroma.
abstract: OBJECTIVE
  We aimed to define the histopathologic features and proliferative rate of congenital mesoblastic nephroma (CMN) as a risk factor for recurrence.
  
  
  METHODS
  Fourteen cases of CMN among 138 registered pediatric renal tumors were retrospectively reviewed. The prognostic impact for mitotic rate and Ki67 index was investigated.
  
  
  RESULTS
  There were four (28.6%) classic, six (42.9%) cellular, and four (28.6%) mixed type CMNs, with average Ki-67 counts of 16.75% in the classic CMN, and 53.2% in the tumors with cellular components (both mixed and cellular CMNs). Twelve patients (85.7%) were aged less than six months. Tumors with cellular component showed significantly larger tumor diameter and higher Ki-67 index (p = 0.015 and p = 0.016, respectively). The patient with cellular CMN, whose tumor showed the highest mitotic rate (4.9/HPF), but not the highest Ki67 index (57.4%), died of recurrent disease with distant metastasis.
  
  
  CONCLUSIONS
  Proliferative markers-mitotic count and Ki67 index-have limited value to predict recurrence or metastasis in CMNs with a cellular component.
authors.affiliation: a Department of Pathology , Istanbul Faculty of Medicine, Istanbul University , Istanbul , Turkey.
authors.forename: Evsen
authors.initials: E
authors.lastname: Apaydin
authors.affiliation: a Department of Pathology , Istanbul Faculty of Medicine, Istanbul University , Istanbul , Turkey.
authors.forename: Yasemin
authors.initials: Y
authors.lastname: Ozluk
authors.affiliation: b Department of Pediatric Surgery , Istanbul Faculty of Medicine, Istanbul University , Istanbul , Turkey.
authors.forename: Secil
authors.initials: S
authors.lastname: Yuksel
authors.affiliation: b Department of Pediatric Surgery , Istanbul Faculty of Medicine, Istanbul University , Istanbul , Turkey.
authors.forename: Basak
authors.initials: B
authors.lastname: Erginel
authors.affiliation: c Department of Pediatric Hematology-Oncology , Kanuni Sultan Suleyman Education and Research Hospital , Istanbul , Turkey.
authors.forename: Deniz
authors.initials: D
authors.lastname: Tugcu
authors.affiliation: b Department of Pediatric Surgery , Istanbul Faculty of Medicine, Istanbul University , Istanbul , Turkey.
authors.forename: Alaaddin
authors.initials: A
authors.lastname: Celik
authors.affiliation: a Department of Pathology , Istanbul Faculty of Medicine, Istanbul University , Istanbul , Turkey.
authors.forename: Isin
authors.initials: I
authors.lastname: Kilicaslan
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D004268:DNA-Binding Proteins / Q000378:metabolism; D005260:Female; D005354:Fibrosarcoma / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D019394:Ki-67 Antigen / Q000378:metabolism*; D007680:Kidney Neoplasms / Q000473:pathology*; D008297:Male; D008938:Mitosis; D018201:Nephroma, Mesoblastic / Q000473:pathology*; D020794:Receptor Protein-Tyrosine Kinases / Q000378:metabolism; D012097:Repressor Proteins / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D004268:DNA-Binding Proteins; D019394:Ki-67 Antigen; D012097:Repressor Proteins; D014157:Transcription Factors; D020794:Receptor Protein-Tyrosine Kinases
keywords: Ki-67; mesoblastic nephroma; mitosis; pediatric; renal tumor