From the Guidelines
The patient's current management plan, including annual follow-up imaging with renal sonogram and discussion about UTI prevention, is appropriate and should be continued to monitor the cysts and prevent future urinary tract infections. The patient is an 86-year-old female with recently treated urinary tract infection who is currently asymptomatic. Her renal sonogram showed normal-sized kidneys with multiple bilateral renal cysts, the largest measuring 4.1 cm in the left kidney. One cyst in the right kidney upper pole had a thin septation, but there was no evidence of hydronephrosis, calculi, or renal tumor. According to the KDIGO 2025 clinical practice guideline for the evaluation, management, and treatment of autosomal dominant polycystic kidney disease (ADPKD) 1, the classification of typical ADPKD has prognostic value, but this patient's condition does not appear to fit into the typical ADPKD category. However, the guideline does not provide specific recommendations for simple renal cysts, which are common in older adults.
The international consensus statement on the diagnosis and management of autosomal dominant polycystic kidney disease in children and young people 1 suggests that routine monitoring of cyst growth should not be performed too frequently in asymptomatic patients, as ultrasonography findings are unlikely to influence clinical management decisions. However, this patient's age and the presence of simple renal cysts suggest that annual monitoring is reasonable to ensure stability.
For UTI prevention, the patient should be advised to:
- Maintain adequate hydration
- Practice good hygiene
- Urinate after sexual activity
- Avoid irritating feminine products
- Consider cranberry supplements If she has recurrent UTIs, prophylactic antibiotics might be considered after consultation with her physician. The patient's quality of life and morbidity should be prioritized, and the current management plan appears to be appropriate for achieving this goal.
From the Research
Renal Cysts and Ultrasound Imaging
- The patient's renal sonogram revealed bilateral multiple renal cysts, with the largest cyst in the left kidney measuring 4.1 cm 2.
- One of the cysts in the right kidney upper pole had a thin septation, but there was no evidence of renal tumor 2.
- Ultrasound screening is helpful in distinguishing cystic from solid lesions and monitoring the growth and structural pattern of cysts 2.
- However, detection of small renal carcinoma (< 3 cm in diameter) is limited, and small tumors are detected by conventional ultrasound only in 67-79% of cases 2.
Diagnosis and Treatment
- A diagnosis of a malignant cystic lesion requires evidence of multiple, thickened internal septa, calcifications, vascularity, and parietal nodularity 2.
- The patient was reassured and recommended to repeat renal imaging with sonogram in one year, and urinalysis and urine culture were obtained 2.
- Urinary tract infection prevention was also discussed, highlighting the importance of regular monitoring and preventive measures 3.
Role of Ultrasound in Nephrology
- Ultrasound is commonly used in nephrology for diagnostic studies of the kidneys and lower urinary tract, and to guide percutaneous procedures 3.
- Nephrologists must have a thorough understanding of renal anatomy and the sonographic appearance of normal kidneys and lower urinary tract, and be able to recognize common abnormalities 3.
- Proper interpretation of ultrasound images requires correlation with the clinical scenario, and training and certification in renal ultrasonography are available 3.