title: Prepubertal testicular tumors: a single-center experience of 44years.
abstract: OBJECTIVE
  To present the clinical and histological features of prepubertal testicular tumors (PTTs), the long-term experience of a single institution was reviewed.
  
  
  METHODS
  A total of 62 prepubertal children who were treated for testicular tumors at Kanagawa Children's Medical Center from 1971 to 2014 were retrospectively reviewed. Histopathological findings, age at operation, clinical stage, and outcomes were analyzed. Clinical findings between the two eras, 1971-1990 and 1991-2014, were also compared.
  
  
  RESULTS
  The median age at operation was 17months. Pathology revealed 29 teratomas (47%), 26 yolk sac tumors (42%), 5 epidermoid cysts (8%), 1 Sertoli cell tumor (1.5%), and 1 benign cyst (1.5%). Teratoma was the most common tumor in this series, and children with immature teratomas were operated at a significantly younger age than those with mature teratomas. Yolk sac tumor was the second most common. The clinical stages of yolk sac tumors were stage I in 23 (89%) and stage II in 3 (11%). Clinical findings were not significantly different between the early and late eras.
  
  
  CONCLUSIONS
  To the best of our knowledge, this is the largest single-center study of PTTs in Japan. The most common PTT in this study was teratoma, followed by yolk sac tumor. There was no significant difference in the histological distribution of PTTs between the two eras. Compared with the current data of single-center series in North America, the incidence of yolk sac tumor was markedly higher in the present study. This discrepancy is possibly explained by racial differences.
authors.affiliation: Department of Urology, Kanagawa Children's Medical Center, Yokohama, Japan.
authors.forename: Sayaka
authors.initials: S
authors.lastname: Akiyama
authors.affiliation: Department of Urology, Kanagawa Children's Medical Center, Yokohama, Japan.
authors.forename: Kazuyo
authors.initials: K
authors.lastname: Ito
authors.affiliation: Department of Urology, Kanagawa Children's Medical Center, Yokohama, Japan.
authors.forename: Woo Jin
authors.initials: WJ
authors.lastname: Kim
authors.affiliation: Department of Pathology, Kanagawa Children's Medical Center, Yokohama, Japan.
authors.forename: Yukichi
authors.initials: Y
authors.lastname: Tanaka
authors.affiliation: Department of Urology, Kanagawa Children's Medical Center, Yokohama, Japan. Electronic address: yuichiroy@gmail.com.
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Yamazaki
mesh_terms: D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D003884:Dermoid Cyst / Q000453:epidemiology / Q000473:pathology; D018240:Endodermal Sinus Tumor / Q000453:epidemiology / Q000473:pathology; D004814:Epidermal Cyst / Q000453:epidemiology / Q000473:pathology; D006801:Humans; D015994:Incidence; D007223:Infant; D007564:Japan / Q000453:epidemiology; D008297:Male; D012189:Retrospective Studies; D013724:Teratoma / Q000453:epidemiology / Q000473:pathology; D013736:Testicular Neoplasms / Q000453:epidemiology / Q000473:pathology; D013997:Time Factors
keywords: Pediatrics; Teratoma; Testes; Testicular neoplasms; Yolk sac tumor