一名 76 岁男子因咳嗽被转至我们医院。胸部计算机断层扫描 (CT) 显示左上叶舌段有一个 45 毫米的肿块。经支气管肿瘤活检显示腺癌。增强 CT 和骨闪烁扫描显示肺、胸膜和骨转移。患者被诊断为左上叶腺癌 cT2bN3M1c IVB 期。使用 Oncomine Dx Target Test Multi-CDx 系统对原发肿瘤进行遗传分析，结果显示表皮生长因子受体 (EGFR) (L858R) 和 CTNNB1 突变呈阳性。基于这些发现，患者接受了奥希替尼（80 毫克/天）作为一线治疗。六个月后，肿瘤尺寸增大，表明疾病进展。停止奥希替尼并开始卡铂（曲线 5 下面积）和培美曲塞（500 mg/m2）二线治疗。经过三个周期的化疗后，患者出现痴呆和定向障碍。头部对比增强磁共振成像显示粟粒状脑转移。粟粒性播散是一种罕见的脑转移形式。肺转移的粟粒状模式与 EGFR 外显子 19 缺失密切相关。外显子19缺失的非小细胞肺癌粟粒状脑转移的影像学特征已有报道。据我们所知，这是首例伴有粟粒状脑转移和 EGFR (L858R) 和 CTNNB1 共突变的肺癌病例报告。总之，EGFR (L858R) 和 CTNNB1 的共突变以及 EGFR-酪氨酸激酶抑制剂的停用可能导致粟粒性脑转移的发生。需要进一步的案例研究。© 2023 作者。中国肺肿瘤学组与John Wiley联合出版《胸癌》

A 76-year-old man was referred to our hospital with a cough. Chest computed tomography (CT) revealed a 45-mm mass in the lingular segment of the left upper lobe. Transbronchial tumor biopsies showed adenocarcinoma. Contrast-enhanced CT and bone scintigraphy revealed lung, pleura, and bone metastases. The patient was diagnosed with left upper lobe adenocarcinoma cT2bN3M1c stage IVB. A genetic analysis of the primary tumor using the Oncomine Dx Target Test Multi-CDx system revealed positivity for epidermal growth factor receptor (EGFR) (L858R) and CTNNB1 mutations. Based on these findings, the patient was treated with osimertinib (80 mg/day) as first-line therapy. Six months later, the tumor increased in size, indicating progressive disease. Osimertinib was stopped and second-line therapy with carboplatin (area under the curve 5) and pemetrexed (500 mg/m2) was initiated. After three cycles of chemotherapy, the patient developed dementia and disorientation. Contrast-enhanced magnetic resonance imaging of the head showed miliary brain metastases. Miliary dissemination is a rare form of brain metastasis. Miliary patterns of lung metastases have been strongly associated with the EGFR exon 19 deletion. The radiological features of miliary brain metastases of non-small cell lung cancer with the exon 19 deletion have been reported. To the best of our knowledge, this is the first case report of lung cancer with miliary brain metastases and co-mutations of EGFR (L858R) and CTNNB1. In conclusion, co-mutations of EGFR (L858R) and CTNNB1 and the discontinuation of EGFR-tyrosine kinase inhibitor may contribute to the development of miliary brain metastases. Further case studies are warranted.© 2023 The Authors. Thoracic Cancer published by China Lung Oncology Group and John Wiley & Sons Australia, Ltd.