Giant hydronephrosis complicated by multiple uroepithelial carcinomas.

Giant hydronephrosis is uncommon, and malignant hydronephrosis of unknown origin is even rarer. We report a case of a 43-year-old male patient with giant hydronephrosis without painless carnivorous hematuria. Preoperative imaging and urinary search for exfoliated cells revealed no evidence of renal pelvic cancer. The patient underwent simple nephrectomy and pathology confirmed the diagnosis of multifocal high-grade papillary uroepithelial carcinoma of the renal pelvis.