title: Metachronous benign ovarian tumors are not uncommon in children.
abstract: OBJECTIVE
  To evaluate the risk for metachronous ovarian tumor in pediatric patients with mature ovarian teratoma.
  
  
  METHODS
  During 1981-2011, 22 children underwent oophorectomy for mature teratoma at the median age of 11.4 (range 1.5-15.3) years. The patients were followed-up in median 4.4 (range 0.5-25.5) years.
  
  
  RESULTS
  None of the patients had synchronous bilateral tumor at the time of primary operation, but during follow-up five patients (23%) got metachronous contralateral ovarian tumor. The contralateral tumor was observed in median 3.6 (range 1-8.8) years after the primary operation. According to Kaplan-Meier analysis the risk for contralateral tumor was 14% ± 8% (SE) within five years and 66% ± 26% (SE) within 10 years. In this series, the contralateral tumor was operated by ovary preserving surgery. Three of the metachronous tumors were mature teratomas and two were seromucinous infantile cystadenomas. One patient had a second teratoma recurrence 14 years after the first recurrence.
  
  
  CONCLUSIONS
  More than one fifth of the children with ovarian mature teratoma get metachronous benign tumor to the contralateral ovary. Therefore a yearly ultrasound follow-up is needed for these patients up to potential pregnancy to enable early diagnosis, ovary preserving surgery and maintenance of fertility in the case of metachronous tumor.
authors.affiliation: Department of Pediatric Surgery, Children's Hospital, University of Helsinki, Helsinki, Finland. Electronic address: seppo.taskinen@hus.fi.
authors.forename: Seppo
authors.initials: S
authors.lastname: Taskinen
authors.affiliation: Department of Pediatric Surgery, Children's Hospital, University of Helsinki, Helsinki, Finland.
authors.forename: Alda
authors.initials: A
authors.lastname: Urtane
authors.affiliation: Department of Pediatric Surgery, Children's Hospital, University of Helsinki, Helsinki, Finland.
authors.forename: Riitta
authors.initials: R
authors.lastname: Fagerholm
authors.affiliation: Department of Pathology, University of Helsinki, Helsinki, Finland.
authors.forename: Jouko
authors.initials: J
authors.lastname: Lohi
authors.affiliation: Department of Hematology, Oncology and Stem Cell Transplantation, Children's Hospital, University of Helsinki, Helsinki, Finland.
authors.forename: Mervi
authors.initials: M
authors.lastname: Taskinen
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D018291:Cystadenoma, Mucinous / Q000175:diagnosis* / Q000601:surgery; D018293:Cystadenoma, Serous / Q000175:diagnosis* / Q000601:surgery; D055088:Early Detection of Cancer; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D016609:Neoplasms, Second Primary / Q000175:diagnosis* / Q000601:surgery; D010051:Ovarian Neoplasms / Q000175:diagnosis / Q000601:surgery*; D010052:Ovariectomy; D012189:Retrospective Studies; D013724:Teratoma / Q000175:diagnosis / Q000601:surgery*
keywords: Children; Contralateral tumor; Cystadenoma; Metachronous tumor; Teratoma