Multifocal primary intracranial yolk sac tumor in an adult patient: a case report and literature review.

Background: Yolk sac tumor is a type of germ cell tumor. It commonly arises in the gonads but sometimes can occur outside the gonads. Primary intracranial yolk sac tumors were very rare. It is always located in the pineal, suprasellar and posterior third ventricular region. The incidence of yolk sac tumor is estimated as less than 8% of all primary intracranial germ cell tumors. Multifocal primary intracranial yolk sac tumors have seldom been reported. Case Description: Here we reported a 29 years old male patient with a sudden coma and a history of headaches for one month. Computed Tomography and magnetic resonance imaging of the head showed three masses located at the suprasellar region, pineal region and left temporal lobe separately. The mass at the left temporal lobe was successfully resected with emergency surgery, and decompressive craniectomy was also performed. Intraoperative findings revealed that the tumor was a solid mass with intra-tumoral haemorrhage. The pathology examination confirmed the diagnosis of yolk sac tumor. Hematoxylin and eosin staining clearly showed the Schiller-Duval body. Whole-brain radiotherapy was performed after the operation, and the patient died in a local hospital 11 months after the surgery. Conclusions: We reported a case of multifocal primary intracranial yolk sac tumor in an adult patient. Then we reviewed the literature and discussed the treatment and diagnosis of patients with primary intracranial yolk sac tumors.