Intracranial growing teratoma syndrome (iGTS): an international case series and review of the literature

Intracranial growing teratoma syndrome (iGTS) is a rare phenomenon of paradoxical growth of a germ cell tumor (GCT) during treatment despite normalization of tumor markers. We sought to evaluate the frequency, clinical characteristics and outcome of iGTS in Western countries. Pediatric patients from 22 North American and Australian institutions diagnosed with iGTS between 2000 and 2017 were retrospectively evaluated. From a total of 777 cases of central nervous system (CNS) GCT, 39 cases of iGTS were identified for an overall frequency of 5%. Pineal region was a more frequent location for iGTS as compared to cases of GCT without iGTS (p