A rare but misleading cause of hematuria in hemophilia A: renal pelvic hemorrhage mimicking tumor.

Hematuria is a common manifestation in hemophilia A, whereas upper urinary tract bleeding is rare and diagnostically challenging. We report a patient with severe hemophilia A presenting with gross hematuria due to spontaneous renal pelvic hemorrhage (Antopol-Goldman lesion), initially mimicking a urothelial tumor on imaging. The diagnosis was supported by clinical context, imaging characteristics, and response to factor VIII replacement therapy. This case highlights the importance of considering benign hemorrhagic causes in hemophilia patients with atypical imaging findings to avoid unnecessary invasive procedures.