GERM-02. MANAGEMENT STRATEGY FOR CHEMO-REFRACTORY, PROGRESSIVE PEDIATRIC IMMATURE TERATOMA

BACKGROUND: Localized NGGCT, a heterogeneous entity, treated with chemo-radiotherapy harbors an overall survival of around 93% based. Here, we present a case of a child whose immature teratoma progressed on chemotherapy, while tumor markers remain within normal range. Salvage therapy for progressive immature teratoma is variable, and can include surgery, chemotherapy and/or craniospinal radiation. Case: 10 year old boy with precocious puberty presented to the local Emergency room with tonic-clonic seizures. Imaging showed a localized pineal mass, with mixed cystic and solid components. Biopsy results were diagnostic for mixed germ cell tumor with components of immature teratoma. Prior to the start of chemotherapy, serum and cerebrospinal fluid (CSF) tumor markers showed slight elevation of both alpha feto- protein (AFP) and beta-human chorionic gonadotropin hormone (β-HCG). The patient underwent two cycles of chemotherapy per ACNS1123, stratum 1, with normalization of tumor markers. Unfortunately, near the end of Cycle 2 of chemotherapy, patient presented with clinical signs of herniation, and was noted to have significant progression of pineal mass on imaging. Tumor was gross totally resected, with pathology conclusive for only immature teratoma. Pre- and post-operative tumor markers remained normal. Proton-beam craniospinal radiation was then administered. Patient is now almost 6 months off therapy, with unremarkable serum and CSF tumor markers, as well as serial imaging that remains negative for disease, with neurological development appropriate for age. CONCLUSION: This case highlights the unusual nature of progression of an immature teratoma with no elevation of tumor markers while on chemotherapy. While salvage chemotherapy, in the form of a metronomic regimen or high-dose consolidative regimen, can be considered, these do present quite a bit of short-term and long-term toxicity to the growing child. Craniospinal irradiation followed by close monitoring is a reasonable alternative, with less short-term toxicity, for an entity that is radio-sensitive.