Abstract
BACKGROUND: Pulmonary sarcomatoid carcinoma is a rare and highly aggressive variant of non-small cell lung cancer with consistently poor outcomes. While recent evidence has demonstrated the superior efficacy of immunotherapy in pulmonary sarcomatoid carcinoma, particularly in patients with high PD-L1 expression, access to these agents remains restricted in Korea because of insurance limitations. CASE PRESENTATION: A 41-year-old male with a history of malignant peripheral nerve sheath tumour presented with dyspnoea, fever, and a 10 cm right lower lobe lung mass. Despite extensive necrosis complicating initial diagnosis, surgical resection revealed sarcomatoid carcinoma (pT4N0M0) with exceptionally high PD-L1 expression 80%. The patient achieved R0 resection but declined adjuvant therapy. Remarkably rapid recurrence occurred within two months of the surgery, presenting as a 16 cm pleural mass with haemorrhagic necrosis. This is among the earliest recurrences documented following complete pulmonary sarcomatoid carcinoma resection. CONCLUSIONS: Pulmonary sarcomatoid carcinoma requires immediate and optimal therapeutic intervention because of its aggressive nature and narrow therapeutic window. In health care systems with limited access to immunotherapy, emphasis must be placed on achieving complete surgical resection and intensive postoperative surveillance. This case highlights the need for health care policy discussions regarding expanded access to immunotherapy for patients with favourable biomarker profiles, as current restrictions may significantly impact outcomes in this devastating disease.