MR findings of pineal yolk sac tumor in a patient with testicular embryonal carcinoma.

Magnetic resonance imaging features of a rare pineal region yolk sac tumor found in a 31-year-old man with a history of previously treated embryonal cell carcinoma of the testicle are presented. No specific magnetic resonance imaging features that definitely differentiate yolk sac tumor from other pineal region tumors could be found. However, in individuals with a previously established testicular germ cell tumor, a metastatic or secondary primary germ cell tumor should be suspected when there is a newly diagnosed pineal region mass. Serum tumor markers are helpful in confirming the diagnosis of a germ cell tumor.