Conclusion: Although the yolk sac tumor out of gonad have characteristics of malignant tumor by CT scanning, it is still lack of specificity, and need further physiological examination.

• 结论：性腺外卵黄囊瘤的CT影像表现虽具有恶性肿瘤的特点，但缺乏特异性，确诊有赖于病理学检查。