脊索瘤是一种罕见的起源于脊索组织的恶性肿瘤，通常沿脊柱轴发生。关于原发性肺脊索瘤的已发表报告仅有少数。在此，我们介绍一例原发性肺脊索瘤病例，并讨论诊断罕见脊索瘤的重要考虑因素。我们报告一例原发性肺脊索瘤病例，患者为一名 39 岁男性，有睾丸卵黄囊混合生殖细胞瘤和畸胎瘤病史。计算机断层扫描显示左下叶生长缓慢的实性病变。我们对疑似生殖细胞肿瘤肺转移进行了楔形切除术。组织学上，具有嗜酸性细胞质的大圆形或椭圆形细胞被具有颗粒状、轻度嗜酸性细胞质的大细胞包围。肿瘤细胞呈物理性。免疫组织化学显示 brachyury、S-100 蛋白、上皮膜抗原、波形蛋白和细胞角蛋白 AE1/AE3 呈阳性，提示肺脊索瘤。睾丸混合生殖细胞肿瘤的重新检查未发现脊索成分。尽管一些区域的brachyury染色呈阳性，但苏木精和伊红（HE）染色并未显示出脊索瘤的典型形态特征。肺肿瘤的互补荧光原位杂交 (FISH) 证实不存在同染色体 12p 和 12p 扩增。因此，最终诊断为原发性肺脊索瘤。 在有睾丸混合生殖细胞肿瘤病史的患者中，使用肺和睾丸肿瘤的 HE 和 Brachyury 染色比较组织形态学，并使用 FISH 分析肺肿瘤中的同染色体 12p 和 12p 扩增对于罕见肺脊索瘤的诊断至关重要。© 2024。作者。

Chordoma, a rare malignant tumor arising from notochordal tissue, usually occurs along the spinal axis. Only a few published reports of primary lung chordomas exist. Herein, we present a case of primary lung chordoma and discuss important considerations for diagnosing rare chordomas.We report a case of primary lung chordoma in a 39-year-old male with a history of testicular mixed germ-cell tumor of yolk sac and teratoma. Computed tomography revealed slow-growing solid lesions in the left lower lobe. We performed wedge resection for suspected germ-cell tumor lung metastasis. Histologically, large round or oval cells with eosinophilic cytoplasm were surrounded by large cells with granular, lightly eosinophilic cytoplasm. Tumor cells were physaliphorous. Immunohistochemistry was positive for brachyury, S-100 protein, epithelial membrane antigen, vimentin, and cytokeratin AE1/AE3, suggesting pulmonary chordoma. Re-examination of the testicular mixed germ-cell tumor revealed no notochordal elements. Although some areas were positive for brachyury staining, hematoxylin and eosin (HE) staining did not show morphological features typical of chordoma. Complementary fluorescence in situ hybridization (FISH) of the lung tumor confirmed the absence of isochromosome 12p and 12p amplification. Thus, a final diagnosis of primary lung chordoma was established.In patients with a history of testicular mixed germ cell tumors, comparison of histomorphology using HE and Brachyury staining of lung and testicular tumors, and analyzing isochromosome 12p and 12p amplification in lung tumors using FISH is pivotal for the diagnosis of rare lung chordomas.© 2024. The Author(s).