title: Renal cell carcinoma in young adults: a study of 130 cases and a review of previous series.
abstract: OBJECTIVE
  To characterize a large series of renal cell carcinomas (RCCs) in young patients and to compare the data obtained to previously published data.
  
  
  METHODS
  A total of 130 RCCs diagnosed in patients <40 years of age were collected from 9 different hospitals in Spain. Cases were re-evaluated following the diagnostic criteria of the 2004 WHO classification of renal tumors.
  
  
  RESULTS
  Histologically, tumors were classified as clear cell (50.7%), papillary (8.5%), chromophobe (14.6%), unclassified (16.9%) and clear cell papillary (9.3%) RCCs. Organ-confined disease (OCD) was detected in 83.6% of the cases. Tumor size and Fuhrman's grade were statistically correlated (Spearman's rho = 0.391). CD10 (p = 0.000), CK7 (p = 0.000), CD15 (p = 0.016), CD117 (p = 0.000), 34betaE12 cytokeratin (p = 0.034) and e-cadherin (p = 0.000) immunostaining significantly differentiated the five histological categories.
  
  
  CONCLUSIONS
  OCD was more common in young RCC patients. The clear cell phenotype accounted for only 50% of RCCs in this age group, with an increasing number of chromophobe and unclassified RCCs. Clear cell RCCs with a papillary growth pattern accounted for a significant proportion of the cases.
authors.affiliation: Departments of Pathology, Hospital de Cruces-Osakidetza, Basque Country University (EHU/UPV), Barakaldo, Bizcaia, Spain. joseignacio.lopez@ehu.es
authors.forename: José Ignacio
authors.initials: JI
authors.lastname: López
authors.forename: Virginia
authors.initials: V
authors.lastname: Moreno
authors.forename: Huberto
authors.initials: H
authors.lastname: García
authors.forename: Iosu
authors.initials: I
authors.lastname: Antón
authors.forename: Antonio
authors.initials: A
authors.lastname: Robles
authors.forename: Juan M
authors.initials: JM
authors.lastname: Oñate
authors.forename: Angeles
authors.initials: A
authors.lastname: Baños
authors.forename: Jorge
authors.initials: J
authors.lastname: Escandón
authors.forename: Aitziber
authors.initials: A
authors.lastname: Ugalde
mesh_terms: D000293:Adolescent; D000328:Adult; D002292:Carcinoma, Renal Cell / Q000473:pathology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007680:Kidney Neoplasms / Q000473:pathology*; D008297:Male; D012189:Retrospective Studies; D055815:Young Adult