Abstract
INTRODUCTION: Primary pure choriocarcinoma of the bladder is extremely rare and should be distinguished from urothelial carcinoma. GATA-3 is a zinc finger transcription factor and a known sensitive immunostaining marker for urothelial carcinoma. However, its accuracy in the detection of urothelial carcinoma is moderate and it is also an important factor in trophoblast differentiation. CASE PRESENTATION: A 78-year-old man presented with asymptomatic gross hematuria for 6 months. Cystoscopy and clinical imaging revealed local bladder carcinoma. He underwent a radical cystectomy and histological diagnosis revealed pure choriocarcinoma (pT2aN0M0) with positive immunostaining, indicating GATA-3 was present. Systemic chemotherapy could not be applied due to his poor general condition, and he died 7 months after surgery. CONCLUSION: We reported the first case of pure choriocarcinoma of the bladder, which showed positive immunostaining results indicating the presence of GATA-3.