A Case of Pseudo-progression-like Pleurisy After Combined Treatment with Nivolumab and Ipilimumab for Lung Adenocarcinoma

Abstract

━━ Background. The frequency of pseudo-progression caused by immune-checkpoint inhibitors in non-small cell lung cancer (NSCLC) is approximately 5%. Thus far, most reports of pseudo-progression in NSCLC have been due to immune-checkpoint inhibitor monotherapy. We report a case of pseudo-progression-like pleurisy after combined treatment with nivolumab and ipilimumab for lung adenocarcinoma. Case. A 70-year-old man with adenocarcinoma (pT3N0M1a, stage IVA) with pleural dissemination received combination therapy consisting of carboplatin, pemetrexed, nivolumab, and ipilimumab as first-line treatment. After treatment, he had fever, dyspnea, elevated CRP, and developed pleural effusion on the affected side. Thoracic drainage was subsequently performed. Abundant T lymphocytes with predominant CD4-positive cells infiltration were observed in pleural fluid cell-block specimens. Afterwards, his symptoms improved. No further accumulation of pleural effusion was observed, even though he continued receiving chemotherapy. Hence, he was diagnosed with pseudo-progression rather than an immune-related adverse event (irAE). Conclusion. This is the first report of pseudo-progressionlike pleurisy in a lung cancer patient after combined nivolumab and ipilimumab treatment. It is important to distinguish pseudo-progression from irAE-induced pleurisy.