Successful treatment of metastatic bladder pleomorphic giant cell carcinoma with pembrolizumab

Introduction Bladder pleomorphic giant cell carcinoma is a rare and aggressive malignancy with a poor prognosis. There are no reports of immune checkpoint inhibitors for bladder pleomorphic giant cell carcinoma to date. Case presentation A 72-year-old man presented with gross hematuria due to multiple bladder cancers. Despite transurethral bladder resection and intravesical injection of Bacillus Calmette-Guerin, bladder cancer recurred. Nineteen months later, he underwent total cystectomy. Pathological examination revealed bladder giant cell carcinoma. Twenty-eight months later, pembrolizumab was administered due to para-aortic lymph node metastasis. Forty-four months later, the lymph node metastasis disappeared, and pembrolizumab administration was terminated. Fifty-eight months later, the patient has remained in remission at the time of writing. Conclusion Immune checkpoint inhibitors manifest a therapeutic potential in bladder pleomorphic giant cell carcinoma.