Neuroradiology case of the day. Malignant mixed germ cell tumor with yolk sac and teratomatous components

Clinical management of teratoma, a rare hypothalamic-pituitary neoplasia

Intracranial teratomas are rare and comprise about 0.5 % of all intracranial tumours. Actually, a total of 15 cases of sellar-suprasellar teratoma have been described in the last 24 years. Although rare, hypothalamic-pituitary teratomas should be taken into account in the differential diagnosis of hypothalamic-pituitary region tumours. The current review focuses on the clinical and therapeutic management of pituitary region teratomas. Teratomas occur more frequently in children and young adults than in the older population and in males as compared to females. Symptoms at diagnosis are usually neurological defects, diabetes insipidus and hypopituitarism. Teratoma diagnosis can be suggested though neuroimaging findings. Magnetic resonance imaging remains the preferred modality for assessment of teratoma. Neuro-radiological findings of mixed-density mass, usually with mixed cystic and solid components or inclusions of teeth, fat and calcification can be suggestive. Tumour markers as beta-HCG and alpha-FP can be useful at teratoma diagnosis for distinguishing immature teratomas, mixed GCTs and mature teratomas with immature or malignant components. Optimal treatment for mature teratoma is neurosurgical excision. Radical excision is advocated as recurrence rate for a mature teratoma is extremely low in cases of complete resection and long-term outcome is excellent. During post-treatment follow-up, in cases of healing, according to tumour marker evaluation and contrasted MRI findings, hormone replacement therapy should be considered, also for secondary hypogonadism and GH deficit, with a more intense follow-up. However, as actually few evidence are available, safety data have to be confirmed also trough a surveillance study.