[Spontaneous rupture of a simple renal cyst to the pyelocalyceal system. Evolution from Bosniak I to IIF].

OBJECTIVE

To report the spontaneous rupture of a renal cyst into the adjacent pyelocalyceal collecting system.

METHODS

We present the case of a 47 year old woman with a 17 centimeter simple renal cyst (Bosniak I) as well as ipsilateral nephrolithiasis. The patient had a febrile urinary tract infection with flank pain. A subsequent CT scan revealed that this cyst spontaneously ruptured into the renal pelvis.

RESULTS

Follow up evaluations showed the former cyst has decreased in size and contain thick and nodular calcifications. At present it is a Bosniak IIF cyst.

CONCLUSION

Simple renal cysts can spontaneously rupture and drain into the adjacent renal collecting system.