Abstract: Objective  To investigate the clinical and pathological characteristics of sellar chondroid chordoma and discuss differential diagnosis of sellar chondroid chordoma with literature review.  Methods  The clinical manifestations of a patient with chondroid chordoma occurring in sellar area were stated. The morphological characteristics and immune phenotype were analyzed by using HE and immunohistochemical staining, and related literatures were reviewed. Results  A 66-year-old male mainly presented with repeated hyponatremia. MRI revealed a well-circumscribed, round and space-occupying mass in sellar area. The tumor was removed under endoscope via the right nasal cavity. During the resection, the tumor could be seen locating in sellar region with solid, tough quality and clear boundaries. Histologically, part of the tumor showed the chondroid differentiation in classical chordoma. The immunohistochemistry of this tumor was positive for cytokeratin (CK), epithelial membrane antigen (EMA) and S-100 protein (S-100), and Ki-67 labeling index was about 1%. The pathological diagnosis was sellar chondroid chordoma. During the follow-up period of 11 months, the patient was in good condition and no tumor recurrence was found.  Conclusions  Despite low incidence, chondroid chordoma usually develops in the midline regions with distinctive histological features and immunohistochemical phenotypes. In general, the prognosis is better than general type of chordoma, and the diagnosis should be differentiated from general types of chordoma and chondrosarcoma.

Key words: Chordoma, Chondrocytes, Sella turcica, Immunohistochemistry

摘要： 目的 探讨鞍区软骨样脊索瘤的临床病理学特征，复习相关文献。方法与结果 男性患者，66 岁。临床表现为反复性低钠血症，MRI 显示鞍区类圆形、边界清楚占位性病变。经右侧鼻腔入路行内镜下鞍区肿瘤切除术，术中可见肿瘤呈实性，质地坚韧，边界清楚；组织形态学表现为典型的脊索瘤组成，肿瘤组织内呈灶性软骨样分化；肿瘤细胞表达细胞角蛋白、上皮膜抗原和S-100 蛋白，Ki-67 抗原标记指数约为1%，病理诊断为鞍区软骨样脊索瘤。术后随访11 个月，一般状况良好，肿瘤无复发。结论 软骨样脊索瘤多生长于中轴骨骼，具有特殊的组织学构象和免疫表型，患者预后较典型脊索瘤好，诊断时应注意与典型脊索瘤和软骨肉瘤相鉴别。

关键词: 脊索瘤, 软骨细胞, 蝶鞍, 免疫组织化学