Bladder cancer metastasis producing beta‐human chorionic gonadotropin, squamous cell carcinoma antigen, granulocyte‐colony stimulating factor, and parathyroid hormone‐related protein

INTRODUCTION: In urothelial cancer, several paraneoplastic syndromes can be triggered by the aberrant expression of hormones, growth factors or lymphokines by tumor cells. CASE PRESENTATION: A 71‐year‐old female patient underwent radical cystectomy for muscle‐invasive urothelial cancer. Shortly after the operation, the patient presented with a leukemoid reaction and hypercalcemia. Computed tomography scans revealed a rapidly progressing tumor on the left pelvic side, and serum levels of granulocyte‐colony stimulating factor, parathyroid hormone‐related protein, and beta human chorionic gonadotropin were elevated. The patient also tested positive for serum squamous cell carcinoma antigen. Hypercalcemia was successfully treated with denosumab. However, the patient's leukocyte counts steadily increased, her condition deteriorated and she passed away. CONCLUSION: To the best of our knowledge, this is the first report of urothelial cancer that tested positive for four tumor markers. The findings support the idea that poorly differentiated bladder carcinomas can ectopically secrete multiple proteins causing pleiotropic paraneoplastic syndromes.