Mature and Immature Extracranial Teratomas in Children: The UK Children's Cancer Study Group Experience

Purpose The purpose of this article is to describe the features, treatment, and risk factors for relapse of children with mature teratoma (MT) and immature teratoma (IT) to assist future treatment plans. Patients and Methods Patients were younger than 16 years of age and referred to the UK Children's Cancer Study Group centers with biopsy-proven extracranial MT and IT and no prior chemotherapy. Complete excision, with the coccyx in sacrococcygeal patients, and follow-up, including serum alpha-fetoprotein monitoring for early detection of malignant yolk sac tumor (YST) recurrence, were recommended. Carboplatin, etoposide, and bleomycin (JEB) were given for YST relapse, whereas relapsed MT and IT were treated at clinicians’ discretion, usually surgically. Pathology was reviewed and treatments, outcome, and prognostic features assessed. Results There were 351 patients, 227 with MT, 124 with IT. Tumor sites were: testis (n = 53), ovary (n = 130), sacrococcygeal region (n = 98), thorax (n = 23), and other (n =...