Abdomen | ct / ultrasound / mri
Kidney Cyst
A kidney cyst means the scan showed a round or oval fluid-filled area in the kidney. Simple kidney cysts are common and often benign. More complex cysts may need closer review depending on how they look on imaging.
A kidney cyst is a fluid-filled sac in the kidney, often found incidentally.
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What it means
A kidney cyst means the scan showed a round or oval fluid-filled area in the kidney. Simple kidney cysts are common and often benign. More complex cysts may need closer review depending on how they look on imaging.
Also seen as: renal cyst, simple renal cyst.
How common it is
Simple kidney cysts are common, especially with increasing age.
Common age-related incidental finding
Simple kidney cysts are especially common in adults and older patients.
Common causes
- Simple benign renal cyst
- Age-related cyst formation
- Complex cyst needing characterization
- Less commonly, a cystic kidney mass
When doctors worry
- The cyst is described as complex or enhancing
- The report recommends Bosniak characterization
- There are symptoms or kidney dysfunction
Typical follow-up
- Simple cysts often need no further action
- Complex cysts may need dedicated renal imaging
- Older scans may be reviewed for stability
Example report wording
Simple right renal cyst.
See phrase explanationComplex cystic lesion of the left kidney, further characterization recommended.
See phrase explanation
Common report phrases linked to this finding
Cholelithiasis without evidence of acute cholecystitis.
"Cholelithiasis without evidence of acute cholecystitis." is radiology report language linked to gallstones and is best understood in the context of the full imaging report.
Complex cystic lesion of the left kidney, further characterization recommended.
"Complex cystic lesion of the left kidney, further characterization recommended." is radiology report language linked to kidney cyst and is best understood in the context of the full imaging report.
renal cyst
"renal cyst" is radiology report language linked to kidney cyst and is best understood in the context of the full imaging report.
simple right renal cyst
"simple right renal cyst" is radiology report language linked to kidney cyst and is best understood in the context of the full imaging report.
Common size, location, and severity variations
Frequently asked questions
Does a kidney cyst mean kidney cancer?
No. Many kidney cysts are simple and benign.
What does simple cyst mean?
It usually means a fluid-filled cyst without suspicious internal features.
Related symptom guides
These educational symptom pages explain search-intent questions that often overlap with this finding.
Clear medical disclaimer
Educational information only. Always consult your clinician for medical advice.
This page is educational only and should be used to understand report language, not to diagnose a condition or replace clinician review.
Sources
Sources and medical review process
RadDx finding pages are written for patient education using consumer-friendly radiology references, plain-language terminology resources, and cautious summary review of common imaging follow-up frameworks.
- Reviewed by
- RadDx Editorial Team
- Last reviewed
- March 10, 2026
- RadiologyInfo.org
RSNA and ACR
- MedlinePlus
U.S. National Library of Medicine
- NCI Dictionary of Cancer Terms
National Cancer Institute
Sources are used for patient education context and terminology support. They do not replace clinician review of your individual report.
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