ID #1066 A Multicentre Case Series on Ventriculoperitoneal Shunt-Related Peritoneal Metastases from Intracranial Germ Cell Tumours

Background Peritoneal metastases from intracranial germ cell tumours (GCTs), via ventriculoperitoneal (VP) shunt tracts, are rare and historically portend a dismal prognosis. Awareness is paramount for early detection through vigilant monitoring of abdominal symptoms and tumour markers in shunted patients, which may facilitate timely intervention and improve outcomes. Methods We present three paediatric GCT cases from international centres who developed VP shunt-related peritoneal metastases. Results Case 1 (Hong Kong): A 19-year-old male with VP shunt had relapsed multifocal germinoma and diffuse ventricular spread, and was previously treated with 2 cycles of cisplatin (P), etoposide (E) and ifosfamide (I) followed by high-dose chemotherapy and stem cell rescue (HD-HSCT), then proton craniospinal irradiation (CSI). He presented with abdominal distension 7 months later and was found to have combined ventricular and peritoneal metastasis with biopsy-confirmed germinoma. Salvage therapy with gemcitabine, paclitaxel, irinotecan and vinblastine was initiated, with a plan for subsequent HD-HSCT. Case 2 (Canada) A 13-year-old female with suprasellar non-germinomatous GCT (high CSF bHCG >400IU/L) and spinal metastasis, treated with chemoradiotherapy, had peritoneal relapse 12 months later with elevated AFP with yolk sac histology. She was successfully salvaged with 2 cycles of paclitaxel (T), ifosfamide (I) and cisplatin (P), 1 cycle of TI and 2 courses of HD-HSCT, resulting in normalised AFP and sustained remission for 3 months now. Case 3 (USA) A teenage girl with a history of intracranial germinoma on routine surveillance was found to have intraperitoneal metastases related to her VP shunt. She was treated with 4 cycles of carboplatin (C) and etoposide (E) followed by HD-HSCT and has remained in remission for 4 years. A literature review revealed that intraperitoneal metastases from intracranial germ cell tumours (GCTs) via VP shunts are rare but documented[1][2][3][4][5][6][7]. These metastases historically portend poor prognosis, though recent advances in chemotherapy and high-dose regimens with stem cell rescue have improved outcomes. Early detection through vigilant monitoring of abdominal symptoms and tumour markers remains critical for timely intervention. Conclusions These cases provide compelling evidence that chemotherapy can achieve durable remission in intracranial GCTs with peritoneal metastases. Critically, this series underscores the necessity for heightened clinical awareness of VP shunt-related peritoneal spread as a potential complication. 1. Murray, M.J., et al., Intra-abdominal metastasis of an intracranial germinoma via ventriculo-peritoneal shunt in a 13-year-old female. Br J Neurosurg, 2011. 25(6): p. 747–9. 2. H.Rickert, C., Abdominal metastases of pediatric brain tumors via ventriculo-peritoneal shunts. Child’s Nerv Syst, 1998(14): p. 10–14. 3. Rickert, C.H., Extraneural metastases of paediatric brain tumours. Acta Neuropathol, 2003. 105(4): p. 309–27. 4. M.R.Back, B.H., J.Rutgers, S. French, T. C. Moore, Metastasis of an intracranial germinoma through a ventriculoperitoneal shunt: recurrence as a yolk-sac tumor. Pediatr Surg Int, 1997(12): p. 24–27. 5. Shih, Y.-L., D.-W. Chang, and H.-W. Gao, Intracranial germ cell tumor metastasis to the peritoneal cavity through the ventriculoperitoneal shunt. Journal of Medical Sciences, 2020. 40(3). 6. Haimovic, I.C., et al., Metastasis of intracranial germinoma through a ventriculoperitoneal shunt. Cancer, 1981. 48(4): p. 1033–6. 7. Zuo, C., et al., Reflections on Preventive and Therapeutic Strategies on Metastatic Germinoma in Abdomen: A Case Report and Literature Review. Research Square, 2021.