What happened, in summary

A 65-year-old woman had surgery for left upper-lobe lung cancer with left upper lobectomy, wedge bronchoplasty, and ND2a-2 lymph-node dissection. After surgery, she developed chylothorax, a lymphatic-fluid leak into the chest. A low-fat dietary approach did not resolve it, but lymphangiography with lipiodol successfully closed the leak. Pathology showed p-stage IIIA non-small cell lung cancer, and PD-L1 expression was 20% by the 22C3 assay. On postoperative day 59, she began adjuvant cisplatin plus vinorelbine and completed 4 cycles. CT imaging afterward showed no recurrence. She then received atezolizumab as adjuvant immunotherapy. After the first cycle, she developed fever by day 9, then breathlessness and grade 3 hypoxia by day 15. Chest CT showed marked lymphostasis, mainly in the right lower lobe. Lung-cancer spread through lymphatics, infection, and heart failure were ruled out, and the episode was diagnosed as immune-related lymphangitis in the setting of prior chylothorax treatment and immune-checkpoint inhibition. She received 1000 mg methylprednisolone starting on day 15, and the chest X-ray had completely improved by day 8 of steroid treatment. Around the same time, she developed acute inflammatory demyelinating polyneuropathy, another immune-related toxicity, and received intravenous immunoglobulin after steroid therapy. Atezolizumab was stopped after 1 dose. She was then observed without further treatment and remained free of lung-cancer recurrence for more than 1 year. The neurologic toxicity caused difficulty walking and abnormal limb sensations, which gradually improved after treatment. Because both major complications occurred after the first atezolizumab exposure, ongoing management shifted from escalation of cancer therapy to careful observation and toxicity recovery.