AFP and yolk sac tumor: In addition, studies have shown that ZBTB16 is a sensitive and specific marker for yolk sac tumors and is diagnostically superior to AFP.[10] On MRI, yolk sac tumors usually appear as large cystic-solid masses with smooth margins, the bright dot sign is a common finding and is seen at contrast-enhanced MR imaging as enhancing foci in the wall or solid components.[11] On T1WI, areas of hemorrhage exhibit high intensity, which is important to consider for yolk sac tumor in relatively young women.