Successful Immunochemotherapy for Advanced Lung Adenocarcinoma Obstructing the Left Brachiocephalic Vein Complicated by Chylothorax.

A 67-year-old male patient presented with enlarged mediastinal lymph nodes, which compressed and obstructed the left brachiocephalic vein. He also developed a chylothorax in the left pleural cavity. A biopsy of the mediastinal lymph nodes confirmed the diagnosis of lung adenocarcinoma with high programmed death-ligand 1 expression. Due to the presence of metastasis in both bilateral supraclavicular lymph nodes, curative radiation therapy was not feasible. Consequently, carboplatin, nab-paclitaxel, and atezolizumab were administered, and palliative radiation was added sequentially for the mediastinal lymph nodes. A reduction in mediastinal lymph nodes and pleural effusions was observed within 2 weeks. Subsequently, the patient achieved complete remission, including lesions outside the radiated area, and had no recurrence of pleural effusion 24 months after the initial immunochemotherapy, indicating the durable efficacy of an immune checkpoint inhibitor.