MR：肿物边界清楚，考虑椎管内硬膜下脊膜瘤。

IHC：vim、S100、CD99+，Ki67  40%+，PR部分+。

CK  HMB45 GFAP  EMA NSE CgA  Desmin  LCA阴性

请问这是什么类型肿瘤，PNETs还是脊膜瘤、恶性神经鞘瘤？

 形态学小圆细胞肿瘤弥漫分布+免疫组化结果CD99阳性，考虑PNET.

 If CD99 positive, you got a big challenge, need to rule out PNET, please check if there is any lesion in the brain. and stain synaptophysin please and if possible do FISH for 11:22 translocation.

 S-100阳性，细胞分化好，考虑神经内分泌肿瘤。

 Location is not right for chordoma, do you have any immunostains?

The pictures show here favor a lymphoma, low grade. please run the immunostains.

 淋巴瘤？分型、免疫组化。