男性，20岁。入学查体，胸透发现左侧胸腔第6胸椎旁有直径约6cm圆形肿块影。最可能的诊断是（）

A.中央型肺癌

B.胸腺瘤

C.畸胎瘤

D.神经源性肿瘤

E.淋巴源性肿瘤

( )can be issued by the entry-exit inspection and quarantine authorities of the P．R．of China.

A．B/L
B．Certificate of Origin
C．UC
D．Packing List