# Assessment of Incidental Renal Cysts in Adults Undergoing Abdominal CT for Non-urological Indications

## TL;DR

This study finds that incidental kidney cysts are common in adults undergoing abdominal CT scans for unrelated reasons, with most being benign and requiring no further testing.

## Contribution

The study provides new prevalence data on incidental renal cysts in non-urological abdominal CT scans and evaluates their clinical significance using the Bosniak classification.

## Key findings

- Incidental renal cysts were found in 30.8% of patients undergoing abdominal CT for non-urological reasons.
- Most cysts (77.2%) were classified as simple (Bosniak I) and did not require follow-up.
- Older age, male gender, hypertension, and smoking history were associated with the presence of renal cysts.

## Abstract

Background

When abdominal CT scans are performed for reasons other than problems with the urinary tract, renal cysts are frequently seen. The objective of this study was to determine how common renal cysts are during CT imaging for other medical reasons in adult patients.

Methods

This study was conducted as a prospective cross-sectional study with 120 adults who were having abdominal CT scans for conditions such as those of the intestines, liver, or blood vessels. People with a history of kidney disease were not included in the study. All cysts were measured based on their number, size, diameter, and classification using Bosniak standards. Statistical Package for the Social Sciences (SPSS) v26.0 and OpenEpi v3.0.0 were used for performing statistical analyses via chi-square and t-tests with p-value < 0.05.

Results

Incidental renal cysts were present in 37 (30.8%) of the 120 (100%) patients. About three-quarters (28; 77.2%) of the cysts were simple (Bosniak I), with an average size of 22.4 ± 9.1 mm, and most (31; 82.6%) appeared on only one side. There were 6 (16.3%) minimally complex cysts (Bosniak II) that were a little larger than others, with an average size of 29.5 ± 10.4 mm. The most complex cysts (Bosniak IIF/III) represented 2 (6.5%) of the cases and had the largest average size of 33.2 ± 12.7 mm. In addition, patients with cysts were older on average, at 64.8 ± 11.2 years, compared to those without cysts, whose presence of renal cysts was strongly connected to being male (24; 65.2%) vs. 38 (45.7%), having hypertension (23; 63.0%) vs. 31 (37.5%) and having a history of smoking (17; 44.6%) vs. 26 (31.3%). All patients with Bosniak IIF/III cysts were told to have follow-up imaging, but those with Bosniak I cysts didn’t need any follow-up.

Conclusion

Most of these cysts found in the kidney are benign and often occur in the elderly. When we apply the Bosniak classification, we reduce unnecessary checks and tests for the patient. Clinicians ought to weigh each case by risk to avoid carrying out numerous tests on normal cysts.