Germ cell tumours in children and adolescents

Germ cell tumours (GCTs) comprise a heterogeneous group of tumours believed to arise from the totipotent primordial germ cell. While uncommon, they may present at any age from in-utero to young adulthood. Prognosis is generally good and considering them in the differential diagnosis of midline as well as gonadal masses may prevent diagnostic delay and/or escalation of potentially harmful treatment. In childhood, approximately 50% are gonadal and 50% extragonadal (20% intracranial/30% extracranial). Clinical presentation relates to mass effect at tumour site. Teratomas account for 50% of paediatric GCTs and, whilst considered benign, may recur if not completely excised. Malignant GCTs often secrete the tumour markers alpha-fetoprotein and human chorionic gonadotrophin, which may help in diagnosis and follow-up. Outcomes are generally good with >90% five-year overall survival. Management involves complete surgical resection for teratomas and non-metastatic gonadal tumours. In the UK, chemotherapy is reserved for stage 2-4 extracranial malignant GCTs. Intracranial tumours typically occur in the midline in the pineal and/or suprasellar regions. Intracranial germinomas are cured in >90% cases with radiotherapy or combined chemo-radiotherapy. About two-thirds of non-germinomatous intracranial tumours are cured with combined chemo-radiotherapy. Current issues relating to the diagnosis and management of teenagers and young adults with GCTs are highlighted.