摘要目的：报道2例2013版WHO软组织和骨肿瘤分类新增加的罕见病种：良性脊索细胞瘤（BNCT），探讨其临床、影像和病理学特征及病理鉴别诊断。方法收集2例良性脊索细胞瘤的临床及影像学资料，通过光镜观察及免疫组织化学EnVision法分析其临床、影像学、病理学特征、免疫表型及病理鉴别诊断，并复习相关文献。结果例1为53岁的男性患者，例2为61岁的女性患者，影像学均为第5颈椎椎体信号异常，病变局限于骨内，无软组织肿块。镜下均为骨小梁间隙内片状分布的空泡状“脂肪样”细胞，边界清楚，胞质透明，细胞核中位或偏位，无异型性，未见核分裂象；细胞外无黏液样基质形成，缺乏分叶状结构；病变周围骨小梁常有硬化。结论良性脊索细胞瘤的好发部位及免疫表型与脊索瘤相似，但两者影像学及病理形态表现均不相同，并且有不同的治疗原则与预后，两者的鉴别有赖于影像、临床及病理的密切配合。

abstractsObjective To report 2 rare cases of benign notochordal cell tumor ( BNCT) , according to WHO classification of tumors of soft tissue and bone (4th edition).Their radiologic and clincopathologic features and differential diagnosis were investigated.Methods Two cases of BNCT were studied by retrospective review of the clinical , radiologic, pathologic and immunophenotypical findings.Related literatures were reviewed at the same time.Results Case 1 was a 53-year-old man, and case 2 was a 61-year-old woman.Radiographically , both patients presented with abnormal imaging findings in the fifth cervical vertebral body with the lesions located within the bone but without extra osseous mass .Histopathologically , the lesions lacked lobular architecture and extracellular myxoid matrix.The tumor cells were vacuolated and had centrally or peripherally placed round or oval nuclei with small nucleoli , mimicking mature adipocytes.No cytological atypia or mitotic figures were seen.The affected bone trabeculae were sclerotic and islands of bone marrow were often entrapped within the tumor.Conclusions Although sharing similar anatomic distribution and immunophenotype to those of chordoma , BNCT has distinct radiologic and pathologic features and different treatment and prognosis.The differential diagnosis between BNCT and chordoma requires detailed clinical , radiologic and histopathologic evaluations.