Presentation
Left pyelonephritis not settling following 6 days of antibiotics. No significant past history. Normal renal function.
Patient Data
Multiple cystic lesions in both kidneys including a large lesion in the left mid pole containing internal echoes
CT is typical of polycystic disease i.e. large kidneys with multiple cysts. Note mid pole left kidney loculated cyst containing slightly increased density fluid and "fuzzy" margins.
The abnormal cyst went on to be aspirated under ultrasound control which confirmed the presence of pus and thus consistent with an infected cyst.
Case Discussion
Although polycystic kidneys can be daunting to evaluate, one must remember that in addition to cysts they can also harbor other pathology (e.g. tumors, or as in this case infection).