Small cell lung cancer (SCLC) and large cell neuroendocrine carcinoma (LCNEC) have recently been grouped as lung neuroendocrine carcinomas (NECs). Because these lung NECs are clinically malignant and their treatment strategies differ from those of non-SCLC, the quality of diagnosis has a significant prognostic impact. The diagnosis of LCNEC requires positive immunohistochemical staining with chromogranin A, synaptophysin, and CD56, along with a morphological diagnosis, and insulinoma-associated protein 1 (INSM1) has been proposed as an additional marker but is still not an ideal or better marker. We investigated Musashi-1 as a novel immunohistochemical marker in 42 patients with SCLCs and 44 with LCNECs who underwent lung resection between 1998 and 2020 at our institution. We found Musashi-1 expression in 98% (41/42) SCLC and in 90% (40/44) LCNEC. These findings were similar to CD56 expression and superior to synaptophysin, chromogranin A, and INSM1. Musashi-1 also tended to show more diffuse and intense staining, especially in LCNEC, with more cases staining > 10% than any other existing markers (Musashi-1, 77%; INSM1, 45%; chromogranin A, 34%; synaptophysin, 41%; and CD56, 66%). In conclusion, we identified Musashi-1 as a novel immunohistochemical staining marker to aid in the diagnosis of lung NEC.
小细胞肺癌（SCLC）与大细胞神经内分泌癌（LCNEC）近期被归类为肺神经内分泌癌（NECs）。由于这类肺神经内分泌癌具有高度临床恶性，且其治疗策略与非小细胞肺癌存在显著差异，诊断质量对患者预后具有重要影响。目前LCNEC的诊断需依赖嗜铬粒蛋白A、突触素和CD56的免疫组化阳性染色结合形态学诊断，而胰岛素瘤相关蛋白1（INSM1）虽被提议作为补充标志物，但仍非理想或更优的选择。本研究以1998年至2020年间在我院接受肺切除术的42例SCLC患者和44例LCNEC患者为对象，探讨Musashi-1作为新型免疫组化标志物的价值。结果显示，98%（41/42）的SCLC和90%（40/44）的LCNEC存在Musashi-1表达，其表达情况与CD56相近，且优于突触素、嗜铬粒蛋白A及INSM1。Musashi-1染色往往呈现更广泛而强烈的阳性信号，尤其在LCNEC中，染色范围＞10%的病例比例高于现有所有标志物（Musashi-1为77%，INSM1为45%，嗜铬粒蛋白A为34%，突触素为41%，CD56为66%）。综上，本研究证实Musashi-1可作为辅助诊断肺神经内分泌癌的新型免疫组化标志物。
Musashi-1 Is a Novel Immunohistochemical Marker of Neuroendocrine Carcinoma of the Lung
肿瘤(癌症)患者之家