Abstract
Pulmonary alveolar proteinosis (PAP) is a rare disease characterized by the abnormal accumulation of surfactant-derived substances in the lungs. To the best of our knowledge, the successful treatment of metastatic renal cell carcinoma in patients with PAP has not been reported. Here, we describe such treatment of a patient via avelumab plus axitinib therapy. After four courses of treatment, computed tomography showed size reduction of the pulmonary metastatic nodule and improvement of PAP. This study highlights that avelumab plus axitinib therapy is a safe and effective treatment option for metastatic renal cell carcinoma, even in patients with PAP.