Jackstone calculus within a renal cyst

Jackstone Calculi are rare stones of the urinary tract that have a distinct morphology, that of a child's toy jack. They have typically been found in the bladder, and there have been a few reported cases of Jackstone Calculi found in the renal pelvis or calyx. We present the first reported case of a Jackstone Calculi found within a renal cyst on computed tomography in a patient who presented with unilateral left upper quadrant abdominal pain. It is important to recognize these stones and further understand that their formation is not limited to the bladder and instead, they can be found in any part of the urinary tract prone to urinary stasis. These calculi should be considered in a patient presenting with unilateral upper quadrant abdominal pain.