Abstract
INTRODUCTION: Renal collecting duct carcinoma is often found in advanced cancers and has a poor prognosis. Here, we present the case of symptomatic metastatic collecting duct carcinoma in which we observed an initial therapeutic effect of immune checkpoint inhibitors plus tyrosine kinase inhibitors. CASE PRESENTATION: The patient was a 69-year-old male who was referred to our hospital for examination of a right chest tumor and related pain. Contrast-enhanced computed tomography and tumor biopsy were performed, leading to a diagnosis of collecting duct carcinoma. A combination of pembrolizumab plus axitinib was initiated as first-line therapy; right chest pain decreased, and tumor shrinkage was observed. Seven months after treatment initiation, tumor progression was noted. Cabozantinib was initiated as second-line therapy; however, was discontinued due to patient fatigue. The patient died 15 months after the initiation of treatment. CONCLUSION: For symptomatic metastatic collecting duct carcinoma, pembrolizumab plus axitinib may have initial therapeutic effects.