GATA‐3 expression in primary pure choriocarcinoma of the bladder

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.