总的来说是一个小细胞恶性肿瘤。

成人大脑镰旁的小细胞恶性肿瘤主要有：小细胞胶母、PNET、淋巴瘤、转移性小细胞癌、生殖细胞肿瘤以及小细胞软组织肉瘤（如胚横）

本例需免疫组化进行鉴别，个人首选淋巴瘤和PNET

 同意PNET。但要先排除横纹肌样型脑膜瘤。

 首选PNET

The low-power photos and anatomic location suggest hemangiopericytoma. However, the vascular pattern is not consistent with this possibility. High-power photos seem to show a few plasma cells and small lymphocytes in addition to poorly differentiated neoplastic cells. These neoplastic cells are pleomorphic and they seem to have clear cytoplasm. To me, a vague nested pattern is present. I do not favor a lymphoma. I don't see meningothelial differentiation or true rhabdoid cells to support rhabdoid meningioma. Dura-based PNET is rare, and should be carefully ruled out by immunohistochemical stains (GFAP, synaptophysin, NSE). Metastases certainly need to be ruled out. Is there any known malignancy (such as rhabdomyosarcoma, Ewing sarcoma, synovial sarcoma, paraganglioma, etc) in her clinical history? Please share your immunohistochemical results with us to narrow the search for the final diagnosis.

 翻译：从低倍图像和解剖位置上看像血管外皮细胞瘤。但是血管结构不支持这种可能性。高倍图像在低分化肿瘤细胞之外可见少许浆细胞及小淋巴细胞。肿瘤细胞具有多形性，似乎有透明的胞浆。就我看来，有一个模糊的巢状结构。我不同意淋巴瘤。我没有看到脑膜瘤分化以及真正的横纹肌样细胞来支持横纹肌样脑膜瘤的诊断。硬脑膜发生的PNET很罕见，需要通过免疫组化染色（GFAP, synaptophysin, NSE）仔细地除外。转移瘤肯定也需要除外。在她的病史中是否有已知的恶性肿瘤？如横纹肌肉瘤、尤文瘤、滑膜肉瘤、副节瘤等等。请为我们提供免疫组化结果以集中搜寻正确答案的范围。

 恶性脑膜瘤有可能吗？

 免疫组化及随访最终诊断：嗅神经母细胞瘤

 原发还是转移？

 PENT

 PNET

以下是引用xiaohl在2008-5-4 9:41:00的发言：  原发还是转移？

原发