title: Neonatal benign sacrococcygeal teratoma may recur in adulthood and give rise to malignancy.
abstract: BACKGROUND
  The capacity of neonatal sacrococcygeal teratomas (SCT) to recur is a well-recognized phenomenon. However, only a few studies have reported recurrence of the tumors beyond childhood.
  
  
  METHODS
  A follow-up of patients for the detection of late recurrent SCT was performed in 45 patients, ages 4-43 years (mean, 21.5 years). All of the patients had been operated on in infancy for a benign SCT.
  
  
  RESULTS
  Three adults with persistent or recurrent SCT were found. The recurrent tumors were diagnosed 21-43 years after the initial diagnosis and operative treatment. Two recurrences were histologically benign, and one was malignant. In the patient with the malignant recurrence, the coccyx was not removed primarily. The malignant recurrence was a mucinous adenocarcinoma and probably originated from a preexisting benign epithelial component of the teratoma.
  
  
  CONCLUSIONS
  The capacity of a benign SCT to recur may be retained into adulthood. Follow-up of patients after operation for a SCT, even when the tumor is benign, should extend far beyond infancy. Abdominal radiographs may help detect late recurrent tumors with intrapelvic calcifications. When any recurrence is found, malignancy should be suspected.
authors.affiliation: Children's Hospital, University of Helsinki, Finland.
authors.forename: P
authors.initials: P
authors.lastname: Lahdenne
authors.forename: M
authors.initials: M
authors.lastname: Heikinheimo
authors.forename: V
authors.initials: V
authors.lastname: Nikkanen
authors.forename: P
authors.initials: P
authors.lastname: Klemi
authors.forename: M A
authors.initials: MA
authors.lastname: Siimes
authors.forename: J
authors.initials: J
authors.lastname: Rapola
mesh_terms: D002288:Adenocarcinoma, Mucinous / Q000473:pathology*; D000328:Adult; D001859:Bone Neoplasms / Q000473:pathology*; D002471:Cell Transformation, Neoplastic; D003050:Coccyx; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000473:pathology*; D016609:Neoplasms, Second Primary / Q000473:pathology*; D012445:Sacrococcygeal Region; D013724:Teratoma / Q000473:pathology*; D013997:Time Factors