Spontaneous renal cyst rupture into the pelvicalyceal system.

Spontaneous renal cyst rupture is uncommon. It can rupture into the perinephric space, peritoneum, pelvicalyceal system, or a combination of these locations. We present the case of a 90-year-old male with spontaneous left renal cyst rupture into the pelvicalyceal system presenting with hematuria and urinary retention who was managed conservatively.