Immature teratoma of the ovary in children and adolescents: A multi-institutional study of characteristics and management

Objective: Immature teratoma (IT) of the ovary is an uncommon tumor with controversy regarding management. We aimed to review the characteristics, management and outcome of pure IT of the ovary in pediatric and adolescent females. Methods: A multicenter review was performed by 29 institutions participating in the Pediatric Surgical Oncology Research Collaborative of females aged 0-18 years with pure ovarian IT diagnosed between 2010 and 2022. Patients with additional malignant histology were excluded. Results: We identified 127 females with pure ovarian IT with a mean age of 12 years. Most tumors were stage 1 and 2, and high-grade. Complete surgical staging was performed in 50% of patients and identified abnormal tissue, including IT, mature teratoma and gliomatosis at all sites sampled. Nineteen patients (16%) received chemotherapy. A total of 24 patients had a recurrence (9 multiple), 7 of whom had received postoperative chemotherapy. Nine recurrences were purely malignant, containing IT or yolk sac tumor and 19 patients had a benign recurrence Two-year recurrence-free survival was 82%, and there were 2 mortalities. In multivariable analysis, elevated serum alpha fetoprotein and preoperative tumor rupture were significantly associated with recurrence. Conclusions: Overall survival is excellent despite recurrence in 19% of patients. One third of recurrences were multiple, and mature teratoma was a common finding; therefore, surgical resection at recurrence is recommended. Su