Abstract
An 80-year-old male patient was diagnosed to have squamous cell carcinoma of the lung which had a high level of programmed death-ligand 1 (PD-L1) expression. He was prescribed with intravenously administered nivolumab combined with carboplatin and paclitaxel as the first-line therapy. A rapid remission was achieved with nearly total necrosis and cavitation of the original tumor. However, the successful treatment result was accompanied with pneumonitis most likely as an adverse effect of nivolumab. After discontinuation of nivolumab and starting prednisolone treatment, the pneumonitis was soon brought under control. During the treatment course, temporary exacerbation of the disease status led to an interesting differential diagnosis between hyperprogression and pseudoprogression. Tremendous efficacy of combination immunochemotherapy as the first-line treatment for squamous non-small cell lung cancer (NSCLC) with highly expressed PD-L1 has been well demonstrated in this case.