%0 Journal Article %A Julie My Van Nguyen %A Genevieve Bouchard-Fortier %A Sarah E. Ferguson %A Allan Covens %T How Common Is the Growing Teratoma Syndrome in Patients With Ovarian Immature Teratoma? %D 2016 %R 10.1097/IGC.0000000000000751 %J International Journal of Gynecologic Cancer %P 1201-1206 %V 26 %N 7 %X Objectives Growing teratoma syndrome (GTS) after adjuvant chemotherapy for ovarian germ cell tumors is uncommon, with approximately 60 cases reported in the English literature. The objective of this study was to report clinical parameters including outcomes of patients with a diagnosis of GTS after adjuvant chemotherapy for ovarian immature teratoma (IT).Methods and Materials Patients with a condition diagnosed as ovarian IT between 1999 and 2014 at 2 tertiary-care academic centers were evaluated for the development of GTS. Patients’ demographics, surgical and pathology data, adjuvant treatment, tumor markers, and survival data were collected retrospectively.Results Twenty-six patients were treated for ovarian IT with a median follow-up of 69 months (9–166 months). Of the 15 patients who received adjuvant chemotherapy, 6 developed GTS (crude incidence, 40%; 2- and 5-year cumulative actuarial rates, 40% and 50%, respectively). The median age at diagnosis of ovarian IT was 24 years (17–38 years). The median interval from diagnosis of IT to development of GTS was 20 months (8–42 months). These 6 patients underwent 1 to 4 additional surgeries for management of GTS and were alive without evidence of malignancy after a median follow-up of 90 months (range, 24–166 months).Conclusions The development of GTS after adjuvant chemotherapy for ovarian IT seems to be more common than previously reported in the literature. Clinicians need to be cognizant that the occurrence of rapidly growing masses during or after chemotherapy for ovarian IT raises the possibility of GTS. This highlights the importance of prolonged follow-up with tumor markers and imaging studies in patients with ovarian IT. %U https://ijgc.bmj.com/content/ijgc/26/7/1201.full.pdf