Prevalence and clinical characteristics of simple renal cyst

Association Between Metabolic Syndrome and the Size of Renal Cysts: A Cross-Sectional Study

Background and Aims

Metabolic syndrome (MetS) is associated with the development of several diseases. However, the correlation between MetS and size of renal cysts remains unclear. This research aims to explore the potential connection between them, offering theoretical guidance for clinical prevention and treatment of renal cysts.

Methods

A total of 467 patients diagnosed with renal cysts and admitted to Sir Run Run Hospital, Nanjing Medical University from September 2019 to September 2020 were eventually included in this study. They were divided into the small cyst group (cyst volume≤1.5cm³) and the large cyst group (cyst volume>1.5cm³) based on the median value of cyst volume. Multivariate logistic regression analysis was used to evaluate the association between MetS and size of renal cysts.

Results

Our results indicated that MetS (OR 1.941, 95% CI 1.286-2.927, P=0.002) was positively associated with the size of renal cysts. Additionally, multiple renal cysts (OR 2.259, 95% CI 1.402-3.640, P=0.001) and serum globulin (OR 0.945, 95% CI 0.905-0.987, P=0.011) were positively and negatively related to size of renal cysts, respectively.

Conclusion

Our study reveals the association between MetS and the size of renal cysts. Patients with MetS are more likely to have larger renal cysts. The administration of MetS may help limit the development of renal cysts. Further prospective studies are needed to explore the causal relationship between MetS and renal cysts.

Increased prevalence of kidney cysts in individuals carrying heterozygous COL4A3 or COL4A4 pathogenic variants

BACKGROUND

Clinical variability among individuals with heterozygous pathogenic/likely pathogenic (P/LP) variants in the COL4A3/COL4A4 genes (also called autosomal dominant Alport syndrome or COL4A3/COL4A4-related disorder) is huge; many individuals are asymptomatic or show microhematuria, while others may develop proteinuria and chronic kidney disease (CKD). The prevalence of simple kidney cysts (KC) in the general population varies according to age, and patients with advanced CKD are prone to have them. A possible association between heterozygous COL4A3, COL4A4 and COL4A5 P/LP variants and KC has been described in small cohorts. The presence of KC in a multicenter cohort of individuals with heterozygous P/LP variants in the COL4A3/COL4A4 genes is assessed in this study.

METHODS

We evaluated the presence of KC by ultrasound in 157 individuals with P/LP variants in COL4A3 (40.7%) or COL4A4 (53.5%) without kidney replacement therapy. The association between presence of KC and age, proteinuria, estimated glomerular filtration rate (eGFR) and causative gene was analyzed. Prevalence of KC was compared with historical case series in the general population.

RESULTS

Half of the individuals with P/LP variants in COL4A3/COL4A4 showed KC, which is a significantly higher percentage than in the general population. Only 3.8% (6/157) had cystic nephromegaly. Age and eGFR showed an association with the presence of KC (P < .001). No association was found between KC and proteinuria, sex or causative gene.

CONCLUSIONS

Individuals with COL4A3/COL4A4 P/LP variants are prone to develop KC more frequently than the general population, and their presence is related to age and to eGFR. Neither proteinuria, sex nor the causative gene influences the presence of KC in these individuals.

Association of Kidney Cysts With Progressive CKD After Radical Nephrectomy

RATIONALE & OBJECTIVE

Simple kidney cysts, which are common and usually considered of limited clinical relevance, are associated with older age and lower glomerular filtration rate (GFR), but little has been known of their association with progressive chronic kidney disease (CKD).

STUDY DESIGN

Observational cohort study.

SETTING & PARTICIPANTS

Patients with presurgical computed tomography or magnetic resonance imaging who underwent a radical nephrectomy for a tumor; we reviewed the retained kidney images to characterize parenchymal cysts at least 5mm in diameter according to size and location.

EXPOSURE

Parenchymal cysts at least 5mm in diameter in the retained kidney. Cyst characteristics were correlated with microstructural findings on kidney histology.

OUTCOME

Progressive CKD defined by dialysis, kidney transplantation, a sustained≥40% decline in eGFR for at least 3 months, or an eGFR<10mL/min/1.73m2 that was at least 5mL/min/1.73m2 below the postnephrectomy baseline for at least 3 months.

ANALYTICAL APPROACH

Cox models assessed the risk of progressive CKD. Models adjusted for baseline age, sex, body mass index, hypertension, diabetes, eGFR, proteinuria, and tumor volume. Nonparametric Spearman's correlations were used to examine the association of the number and size of the cysts with clinical characteristics, kidney function, and kidney volumes.

RESULTS

There were 1,195 patients with 50 progressive CKD events over a median 4.4 years of follow-up evaluation. On baseline imaging, 38% had at least 1 cyst, 34% had at least 1 cortical cyst, and 8.7% had at least 1 medullary cyst. A higher number of cysts was associated with progressive CKD and was modestly correlated with larger nephrons and more nephrosclerosis on kidney histology. The number of medullary cysts was more strongly associated with progressive CKD than the number of cortical cysts.

LIMITATIONS

Patients who undergo a radical nephrectomy may differ from the general population. A radical nephrectomy may accelerate the risk of progressive CKD. Genetic testing was not performed.

CONCLUSIONS

Cysts in the kidney, particularly the medulla, should be further examined as a potentially useful imaging biomarker of progressive CKD beyond the current clinical evaluation of kidney function and common CKD risk factors.

PLAIN-LANGUAGE SUMMARY

Kidney cysts are common and often are considered of limited clinical relevance despite being associated with lower glomerular filtration rate. We studied a large cohort of patients who had a kidney removed due to a tumor to determine whether cysts in the retained kidney were associated with kidney health in the future. We found that more cysts in the kidney and, in particular, cysts in the deepest tissue of the kidney (the medulla) were associated with progressive kidney disease, including kidney failure where dialysis or a kidney transplantation is needed. Patients with cysts in the kidney medulla may benefit from closer monitoring.

Safety and Feasibility of Single-Port Nephroscopy Combined with a Needle Electrode Technique to Treat Dorsal Simple Renal Cysts

INTRODUCTION

The aim of this study was to explore the safety and feasibility of single-port nephroscopy combined with a needle electrode technique to unroof single dorsal simple renal cysts (SRCs).

METHODS

This was a retrospective analysis of the clinical data for 18 patients with single dorsal SRCs treated with single-port nephroscopy and a needle electrode technique at Zhongshan City People's Hospital from August 2021 to August 2022. The basic information included the cyst condition, surgical methods and recurrence rate, and follow-up was conducted with CT imaging.

RESULTS

The surgery was successful in all 18 patients. The duration of surgery ranged from 24 to 46 min, with an average of 35.83 ± 1.62 min; the intraoperative bleeding volume ranged from 2 to 20 mL, with an average of 9.0 ± 1.3 mL; and the visual analog scale (VAS) score within 24 h after surgery ranged from 1 to 6 points, with an average of 2.72 ± 0.36 points. There were no significant postoperative complications, such as bleeding, urinary fistula, or infection. All drainage tubes were removed on the first day after surgery. After 1 year of postoperative follow-up, 1 patient experienced recurrence, for a recurrence rate of 5.6%.

CONCLUSION

Single-port nephroscopy combined with a needle electrode technique is a safe, feasible, and effective minimally invasive surgical approach for treating single dorsal SRCs.

The prevalence and associated risk factors of detectable renal morphological abnormalities in acromegaly

PURPOSE

The aim of this study was to investigate the prevalence of simple renal cysts (SRCs) and kidney stone disease (KSD) together with laboratory data in patients with acromegaly through comparisons with healthy subjects, and to examine the possible risk factors associated with these abnormalities in acromegaly.

METHODS

This retrospective, single-center study included 125 acromegaly patients (46.4 ± 11.6 years, 68 females/57 males) and 114 age-sex matched healthy individuals (45.3 ± 12.4 years, 59 females/55 males). Demographic data, clinical history, biochemical and abdominal/urinary system ultrasonographic data of the patients were reviewed.

RESULTS

The SRC prevalence (28.8% vs. 8.8%, p < 0.001) and the longitudinal and transverse lengths of kidneys (p < 0.05) were significantly higher in patients with acromegaly compared to the control group. The presence of acromegaly was determined to increase the risk of SRC formation 12.8-fold. The prevalence of KSD was similar in both the patient and control groups (15.2% vs. 7.9%, p = 0.08). Patients with acromegaly with renal cysts (n = 36) compared to the group without cysts (n = 89) were older, had a higher male gender frequency, a longer pre-diagnosis symptom duration, and a higher incidence of hypertension and diabetes mellitus at the time of diagnosis. The multivariate logistic regression analysis showed that only advanced age and male gender were associated risk factors for SRCs in acromegaly patients.

CONCLUSION

The results of this study showed that acromegaly disease significantly increased the prevalence of SRCs and kidney length compared to the age-sex matched healthy population, while the prevalence of KSD was similar. Advanced age and male gender were seen to be independent risk factors for SRC formation in patients with acromegaly.

Decline in measured glomerular filtration rate is associated with simple renal cyst in Chinese patients with type 2 diabetes

AIMS/INTRODUCTION

Simple renal cysts (SRC) are associated with age, hypertension and hyperuricemia, which are risk factors of renal impairment. This study aimed to investigate the prevalence of SRC and its association with measured glomerular filtration rate (mGFR) in patients with type 2 diabetes mellitus in China.

METHODS

A total of 3,552 patients with type 2 diabetes mellitus admitted to Shanghai Sixth People's Hospital from January 2012 to December 2016 were investigated. All participants were diagnosed as SRC by color Doppler, and all participants were measured for GFR by using dynamic renal scintigraphy with technetium-99m-diethylene triamine peta-acetic acid.

RESULTS

The prevalence of SRC was 17.4% (619 cases). Participants with SRC had significantly lower mGFR values than those without SRC (86.16 ± 26.20 vs 94.88 ± 23.98 mL/min/1.73 m2 , P < 0.001). In 478 participants with unilateral renal cyst, the mGFR of the kidney affected by SRC was significantly lower than that of the unaffected kidney (43.32 ± 13.74 vs 44.18 ± 13.34 mL/min/1.73 m2 , P = 0.014). The participants were divided into four groups according to the quartiles of mGFR level (≥109.50, 93.80-109.49, 76.90-93.79 and <76.90 mL/min/1.73 m2 ). The prevalence of SRC gradually increased with decreasing mGFR level (12.9, 13.9, 16.6 and 27.8%, respectively; P trend <0.01). After adjusting for age, sex, duration of diabetes, hypertension and other potential confounders, the logistic regression showed that SRC was an independent risk factor for impaired GFR (<60 mL/min/1.73 m2 ; odds ratio 1.656; 95% confidence interval 1.451-1.890, P < 0.001).

CONCLUSION

SRC is an independent risk factor for the decrease of mGFR in Chinese diabetes patients, and could affect the renal GFR measured by dynamic renal scintigraphy on the SRC side.

Prevalence of Incidental Extraspinal Findings on MR Imaging of the Lumbar Spine in Adults: A Systematic Review and Meta-analysis

BACKGROUND

Low back pain is common worldwide. MR imaging may identify extraspinal findings that are not related to the proposed clinical question. The prevalence of extraspinal incidental findings and their clinical significance has not been well-established.

PURPOSE

This review aimed to evaluate the prevalence of extraspinal findings on MR imaging of the lumbar spine in adults and the prevalence of clinically significant incidental findings.

DATA SOURCES

A systematic search of MEDLINE and EMBASE was performed, including studies published before June 14, 2023.

STUDY SELECTION

Studies presenting a prevalence of extraspinal findings in patients 16 years of age or older were included.

DATA ANALYSIS

A random effects meta-analysis was used to generate composite prevalence measures of extraspinal findings, patients with extraspinal findings, and clinically significant findings.

DATA SYNTHESIS

Sixteen studies were included in this meta-analysis, with a total of 19,593 patients and 6,006 extraspinal incidental findings. The overall prevalence of extraspinal findings was 19.9% (95% CI, 11.1%-30.7%). Overall, 26.7% of patients had an extraspinal finding identified (95% CI, 14.8%-40.6%). The most common subgroup of extraspinal findings was genitourinary findings in males (27.1%; 95% CI, 25.6%-28.8%). Data from 8 studies demonstrated the prevalence of clinically significant findings at 5.4% (95% CI, 3.2%-8.1%).

LIMITATIONS

Retrospective populations with small numbers of participants in clinically relevant subgroups may result in heterogeneity and imprecision within composite outcome measures.

CONCLUSIONS

Extraspinal findings are common, detected in more than one-quarter of patients. Five percent of findings are clinically significant and may require further action.

CEUS Bosniak Classification-Time for Differentiation and Change in Renal Cyst Surveillance

It is time for a change. CEUS is an established method that should be much more actively included in renal cyst monitoring strategies. This review compares the accuracies, strengths, and weaknesses of CEUS, CECT, and MRI in the classification of renal cysts. In order to avoid overstaging by CEUS, a further differentiation of classes IIF, III, and IV is required. A further development in the refinement of the CEUS-Bosniak classification aims to integrate CEUS more closely into the monitoring of renal cysts and to develop new and complex monitoring algorithms.

Prevalence and associated risk factors of simple renal cysts in primary hyperparathyroidism

PURPOSE

Previous studies have pointed to the role of parathormone (PTH) in the development of simple renal cysts. However, there is insufficient evidence related to simple renal cysts in primary hyperparathyroidism (PHPT). Therefore, this study aimed to evaluate the prevalence and risk factors associated with renal cysts in PHPT patients.

METHODS

In this retrospective study, we included 235 patients treated surgically for PHPT and 147 control subjects. The clinical and physical examination findings, laboratory test results, and neck and urinary system ultrasonography examination findings were evaluated. Postoperative parathyroid adenoma volume and weight were also recorded.

RESULTS

Simple renal cysts were found in 53 PHPT patients (22.6%) and in 15 control subjects (10.2%) (p = 0.002). Kidney stones were found in 33 PHPT patients (14%) and in only seven control subjects (4.8%) (p = 0.004). The presence of PHPT and high PTH levels independently supported the development of a simple renal cyst. Advanced age was determined as a risk factor for the development of simple renal cysts, and the presence of kidney stones was an independent predictor of simple renal cysts in PHPT patients. There was no relationship between the presence of simple renal cysts and the volume and weight of parathyroid adenoma.

CONCLUSION

A diagnosis of PHPT, high PTH levels, advanced age, and kidney stones are independent risk factors for simple renal cysts in PHPT patients. These patients should be evaluated regularly for complications of renal cysts and nephrolithiasis.

Association of simple renal cysts with metabolic syndrome in adults

Background and aims

Metabolic syndrome is common nowadays and may increase risk of hypertension, type 2 diabetes mellitus, cardiovascular complications and even mortality. Renal cysts are also frequently found during routine examination. However, the relationship between simple renal cysts (SRCs) and metabolic syndrome remains unclear. This study aimed to investigate the association of SRCs with metabolic syndrome.

Methods

A total of 16,216 subjects aged ≥18 years were enrolled in this study. SRCs were diagnosed with ultrasonography by finding: sharp, thin posterior walls, a round/oval shape, absence of internal echoes, and posterior enhancement. SRCs were categorized by number (0, 1, and ≥2) and size (<2 and ≥2 cm). Metabolic syndrome was diagnosed according to the consensus statement from the International Diabetes Federation.

Results

In multivariate analysis, SRCs were positively related to metabolic syndrome (OR: 1.18, 95% CI: 1.06-1.34). The risk of metabolic syndrome was higher for SRCs with a number ≥2 (OR: 1.35, 95% CI: 1.08-1.68) and size ≥2 cm (OR: 1.33, 95% CI: 1.10-1.61). When considering the SRC number and size concomitantly, SRCs with a number ≥2/size ≥2 cm (OR: 1.42, 95% CI: 1.02-1.98) or <2/size ≥2 cm (OR: 1.30, 95% CI: 1.04-1.62) were positively related to metabolic syndrome.

Conclusions

Simple renal cysts were found to be related to a higher risk of metabolic syndrome, and the association is more significant in those with larger (sizes ≥2cm) or plural (numbers ≥2) SRCs.

Perioperative characteristics, histologic diagnosis, complications, and outcomes of dogs undergoing percutaneous drainage, sclerotherapy or surgical management of intrarenal cystic lesions: 18 dogs (2004-2021)

BACKGROUND

Canine intrarenal cystic lesions (ICLs) are infrequently reported in the veterinary literature. Several treatment options have been described including cyst fenestration (partial nephrectomy/deroofing) +/- omentalization, sclerotherapy using alcohol as a sclerosing agent, percutaneous cyst drainage (PCD), and ureteronephrectomy. Information regarding presenting clinical signs, physical examination findings, histologic diagnosis and outcomes of dogs with ICLs treated by different methods is limited. Medical records of 11 institutions were retrospectively reviewed to identify dogs that underwent PCD, sclerotherapy, surgical deroofing +/- omentalization, or ureteronephrectomy for management of ICLs from 2004 to 2021. Six weeks postoperative/post-procedural follow-up was required. Cases suspected to represent malignancy on preoperative imaging were excluded. The study objective was to provide information regarding perioperative characteristics, complications, and outcomes of dogs undergoing treatment of ICLs.

RESULTS

Eighteen dogs were included, with 24 ICLs treated. Ten had bilateral. There were 15 males and 3 females, with crossbreeds predominating. PCD, sclerotherapy, deroofing and ureteronephrectomy were performed in 5 (5 ICLs treated), 7 (11 ICLs), 6 (6), and 7 (7) dogs, respectively, with 5 dogs undergoing > 1 treatment. Seven dogs experienced 8 complications, with requirement for additional intervention commonest. PCD, sclerotherapy and deroofing resulted in ICL resolution in 0/5, 3/11 and 3/6 treated ICLs, respectively. Histopathology identified renal cysts (RCs) in 7/13 dogs with histopathology available and neoplasia in 6/13 (4 malignant, 2 benign). Of 5 dogs diagnosed histopathologically with neoplasia, cytology of cystic fluid failed to identify neoplastic cells. Among 7 dogs with histologically confirmed RCs, 4 had concurrent ICLs in ipsilateral/contralateral kidney, compared with 2/6 dogs with histologically confirmed neoplasia.

CONCLUSIONS

Benign and neoplastic ICLs were approximately equally common and cystic fluid cytology failed to differentiate the 2. Among renal-sparing treatments, deroofing most commonly resulted in ICL resolution. Presence of concurrent ICLs in ipsilateral/contralateral kidney does not appear reliable in differentiating benign from malignant ICLs.

Development and external validation of a nomogram for predicting renal function based on preoperative data from in-hospital patients with simple renal cysts

Objective

To develop and validate a nomogram for predicting renal dysfunction in patients with simple renal cysts (SRCs).

Methods

We performed a multivariable logistic regression analysis of an in-hospital retrospective cohort of patients with SRCs in the Urology Department of the First Affiliated Hospital of Anhui Medical University. For prognostic model development, 386 patients with SRCs were enrolled from January 2016 to December 2018. External validation was performed in 46 patients with SRCs from January 2019 to April 2019. The primary outcome was renal dysfunction.

Results

Patients were divided into normal or abnormal estimated glomerular filtration rate groups (293 vs. 93) based on the cut-off value of 90 mL/minute/1.73 m². Logistical regression analysis determined that age, haemoglobin, globulin, and creatinine might be associated with renal dysfunction, and a novel nomogram was established. Calibration curves showed that the true prediction rate was 77.42%, and decision curve analysis revealed that the nomogram was more effective with threshold probabilities ranging from 0.1 to 0.8. The area under the curves were 0.829, 0.752, and 0.888 in the overall training, internal, and external validation cohorts, respectively.

Conclusions

We established a nomogram to predict the probability of developing renal dysfunction in patients with SRCs.

The presence of simple renal cysts is associated with an increased risk of albuminuria in young adults

BACKGROUND/AIMS

The prevalence of simple renal cysts increases with age; however, they are occasionally found in adults aged < 40 years. This cross-sectional study evaluated the clinical significance of simple cysts in young adults, focusing on their associations with hematuria and albuminuria.

METHODS

Adults aged < 40 years who underwent comprehensive medical examination between January 2005 and December 2013 were included. Simple renal cysts were identified by ultrasonography.

RESULTS

Renal cysts were found in 276 of the 5,832 subjects (4.7%). Subjects with medullary sponge kidney (n = 1) or polycystic kidney disease (n = 5) were excluded. A single cyst and multiple cysts were found in 234 (4.0%) and 42 (0.7%) subjects, respectively. Age, high systolic blood pressure, and history of hypertension were independent risk factors for the presence of simple cysts. Simple cysts were not associated with an increased prevalence of hematuria. However, subjects with cysts showed a higher prevalence of albuminuria than those without (11.3% vs. 4.5%, p < 0.001). Multivariate analysis revealed that the existence of simple renal cysts was associated with a 2.30-fold increased prevalence of albuminuria (95% confidence interval, 1.512 to 3.519; p < 0.001) independent of other risk factors.

CONCLUSION

In young adults, the presence of simple renal cysts was independently associated with an increased prevalence of albuminuria. The causal relationship needs to be elucidated in further studies.

Natural history of simple renal cysts: longitudinal CT-based evaluation

PURPOSE

Simple renal cysts are common benign lesions that arise from the renal parenchyma. Cyst growth can lead to confusion as well as concern from patients and referring providers about the need for imaging follow-up or additional evaluation. The purpose of this study was to evaluate the natural history of simple renal cysts and determine the best metric to characterize cyst evolution.

METHODS

222 simple renal cysts in 182 adults (age = 58.4 ± 6.0 years) were longitudinally evaluated on non-contrast CT examinations over a mean interval of 7.5 ± 2.8 years. Axial long axis, surface area, and volume were evaluated at baseline and follow-up CT examinations. Absolute and percent annualized growth rates were computed between CT studies for each parameter.

RESULTS

At baseline CT examinations, mean (± SD) axial long axis, surface area, and volume measurements were 2.5 ± 1.7 cm, 2.5 ± 4.5 cm², and 17.6 ± 52.5 ml, respectively. On follow-up examinations, measurements were 3.4 ± 2.0 cm, 4.2 ± 5.9 cm², and 34.4 ± 92.3 ml, respectively. Significant differences (p < 0.01) were found between baseline and follow-up values for each parameter. The absolute growth rate of each parameter was + 0.1 ± 0.1 cm/year, + 2.1 ± 3.4 cm²/year, and + 2.0 ± 5.6 ml/year, respectively. The percent annualized growth rate for each parameter was +6.5 ± 7.3%/year, +18 ± 24%/year, and +46 ± 100%/year, respectively. Overall, 86% (190/222) of cysts increased in size over time; most notably 78% (174/222) increased by ≥ 6% in volume per year. None of the simple cysts developed septations or solid components on follow-up examinations.

CONCLUSION

The majority of simple renal cysts increase in size over time, which was not associated with the development of complex features. Surface area and volume are the parameters most indicative of cyst growth or regression over time. In patients with enlarging asymptomatic simple renal cysts, no follow-up imaging is indicated.

The Relationship Between Simple Renal Cysts and Renal Function in Patients With Type 2 Diabetes

Introduction: Simple renal cysts (SRCs) are the most common acquired cystic kidney disease, but the relationship between SRCs and renal function has not been clarified in patients with type 2 diabetes mellitus (T2DM).

Methods: A retrospective study was conducted to analyze the clinical features of renal cysts and ultrasound data of the kidney in 4,304 patients with T2DM.

Results: The prevalence of SRCs in patients with T2DM was 21.1%. Compared to patients with no SRCs, patients with SRCs had worse renal function (estimated glomerular filtration rate: 108.65 ± 40.93 vs. 92.38 ± 42.1 ml/min/1.73 m², p < 0.05). After adjusting the confounders, SRC was related to estimated glomerular filtration rate in patients with T2DM [odds ratio = 1.49, 95% confidence interval (1.24, 1.79), p < 0.01]. Age, gout, proteinuria, cerebrovascular disease (CVD), and increased serum phosphorus levels were associated with SRCs in patients with T2DM.

Conclusion: SRCs are associated with worse renal function in patients with T2DM. More attention should be paid to gout, proteinuria, CVD, serum phosphorus levels, and renal function in T2DM patients with SRCs.

Pitfalls in Renal Ultrasound

Ultrasound (US) is replete with pitfalls in technique and interpretation, and renal imaging is no exception. Because US of the kidneys is a very common initial and follow-up imaging examination, it is important to be aware of both common and unusual sources of potential error. This essay will review optimal technique and discuss common overcalls, under calls, and misinterpretations with respect to renal size, hydronephrosis, calculi, cysts, masses, and collections.

Factors Influencing Surgical Outcome in Retrograde Management of Parapelvic Renal Cysts

Objective: To investigate the outcomes of retrograde flexible ureteroscopy in managing parapelvic renal cysts and speculate the factors affecting therapeutic efficacy. Methods: Thirty-eight patients with parapelvic renal cysts were recruited and underwent retrograde flexible ureteroscopy using holmium laser. Parapelvic cysts were divided into peripheral type and central type based on the position of cyst convex to the perirenal tissue. Feasibility and safety were retrospectively evaluated, and cases were analyzed to detect their distinctive characteristics. Independent-sample t-test and chi-square test were undertaken for continuous variables and categorical variables, respectively. Results: Radiologic evidence of success was achieved in 31 (81.58%) cases after a mean follow-up of 14.4 months (range 6-26 months). No significant perioperative complications were identified. There were seven cases with features of peripherally located parapelvic cyst. Four cysts shown as irregular protrusion were unable reduce to less half of previous size. Reductions were recorded in the other three patients with spherically peripheral protrusion. There was significant difference between these two types (p = 0.029). Among the 31 patients with centrally located parapelvic cyst, 28 of these have simple cysts that achieved radiologic success and 3 of the 31 patients were identified as failed cases indicated by renal pelvis enveloped by cyst on radiologic investigation. The success rate of simple cysts was significantly higher than that of the later type (p < 0.001). Conclusion: The location and shape of parapelvic cyst may play a critical role in the radiologic outcome of internal incision and patients with simple central or spherical peripheral cyst may benefit more from retrograde flexible ureteroscopy combined with laser incision.

The association between simple renal cyst and aortic diseases: A systematic review and meta-analysis of observational studies

OBJECTIVE

The objective of this meta-analysis of observational studies was to evaluate the association between simple renal cysts (SRC) and presence of aortic pathology such as aortic aneurysms and dissection.

METHODS

We conducted searches in Ovid MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials from January 1960 to August 2019 to identify observational studies that examined the association between SRCs and any aortic diseases, including aortic aneurysms and dissection. Two reviewers independently extracted the data and assessed the risk of bias. The meta-analysis was performed by STATA 14.1.

RESULTS

In total, 11 observational studies with 19 719 participants were included in this meta-analysis. Compared to individuals without SRCs, patients with SRCs had higher odds of abdominal aortic aneurysm (AAA) (adjusted OR = 2.61, 95% CI 2.34-2.91, P < 0.001, I²   = 0%), ascending thoracic aortic aneurysm (TAA) (adjusted OR = 1.98, 95% CI 1.09-3.63, P = 0.03, I²   = 90.1%), descending TAA (adjusted OR = 3.44, 95% CI, 2.67-4.43, P < 0.001, I²   = 0%), type A aortic dissection (AD) (adjusted OR = 1.98, 95% CI 1.32-2.96, P = 0.001, I²   = 12.9%), and type B AD (adjusted OR = 2.55, 95% CI, 1.31-4.96, P = 0.006, I²   = 76.2%). There was a higher average in the sum of diameter of SRCs among AAA compared to patients without AAA (WMD = 19.80 mm, 95% CI 13.92-25.67, P < 0.001, I²   = 63.8%).

CONCLUSION

SRC is associated with higher odds of aortic diseases including AAA, ascending and descending TAA, type A and type B dissection even after adjusting for confounders.

How safe and effective is laparoscopic decortication of simple renal cysts in elderly patients?

Objective: To investigate the assessment of feasibility and safety of laparoscopic decortication of simple renal cysts in elderly patients.Methods: The data of 114 patients who underwent laparoscopic decortication for simple renal cyst between October 2011 and May 2019 were retrospectively evaluated. Patients' age, gender and ASA scores; operation time; cyst size and location; complications; hospital stays and success rates of operations were recorded.Results: The mean age of the patients were 73.8 ± 8.2 years. Forty-eight (42.1%) of the patients were female and 66 (57.9%) were male. Cysts were localized on the right side in 61 (53.5%) patients and on the left side in 53 (46.5%) patients; and mean cyst size was 72.83 ± 31.13 mm. Also, they were localized on the anterior in 88 (77.2%) patients and on the posterior of the kidney in 26 (22.8%) patients. Preoperative ASA score distributions were ASA-I in 12 patients (10.5%), ASA-II in 31 patients (27.2%), ASA-III in 68 patients (59.7%), and ASA-IV in 3 patients (2.6%). Mean operative time was 41.4 ± 5.6 min. Clavien grade 1 complications were observed in 5 (10.4%) patients. Median hospitalization time was 1 day. No recurrence was occurred in any patient in the postoperative period.Conclusions: Although laparoscopic surgery has some risks and complications for elderly patients, laparoscopic decortication can be applied safely and effectively in treatment of simple renal cyst in that patient population.

Long-term renal function in living kidney donors with simple renal cysts: A retrospective cohort study

Simple (Bosniak I) renal cysts are considered acceptable in living kidney donor selection in terms of cancer risk. However, they tend to increase in number and size over time and might compromise renal function in donors. To clarify their implications for long-term renal function, we characterized the prevalence of renal cysts in 454 individuals who donated at our center from 2000 to 2007. We estimated the association between the presence of cysts in the kidney remaining after nephrectomy (ie, retained cysts) and postdonation eGFR trajectory using mixed-effects linear regression. Donors with retained cysts (N = 86) were older (P < .001) and had slightly lower predonation eGFR (median 94 vs 98 mL/min/1.73 m2 , P < .01) than those without cysts. Over a median 7.8 years, donors with retained cysts had lower baseline eGFR (-8.7 -5.6 -2.3  mL/min/1.73 m2 , P < .01) but similar yearly change in eGFR (-0.4 0.02 0.4  mL/min/1.73 m2 , P = .2) compared to those without retained cysts. Adjusting for predonation characteristics, there was no difference in baseline eGFR (P = .6) or yearly change in eGFR (P > .9). There continued to be no evidence of an association when we considered retained cyst(s) ≥10 mm or multiple retained cysts (all P > .05). These findings reaffirm current practices of accepting candidates with simple renal cysts for donor nephrectomy.

Sex Differences in Kidney Stone Disease in Chinese Patients with Type 2 Diabetes Mellitus

Objectives

To investigate the characteristics of kidney stone disease (KSD) among the Chinese population with type 2 diabetes mellitus (T2DM) and identify sex-specific factors associated with KSD.

Methods

A single-center, cross-sectional analysis was performed among Chinese patients with T2DM. KSD was identified by ultrasonography or computed tomography results. Demographic data, physical measurements, laboratory measurements, comorbidities, and related medication data were collected and analyzed. Binary logistic regression was used to explore the associated factors.

Results

A total of 7,257 patients with T2DM were included in the study, of which 56.1% were male and 15.0% were diagnosed with KSD. The male-to-female ratio for KSD among T2DM patients was 1.35. Among all the T2DM patients, male gender, HOMA2-IR, uric acid, and renal cysts were independent risk factors for KSD development, whereas serum phosphorus and the use of angiotensin-converting enzyme inhibitors (ACEIs) were independent protective factors for KSD. Among male diabetic patients, triglycerides, HOMA2-IR, renal cysts, and urinary tract infections were all associated with a greater risk of KSD. In contrast, serum phosphorus was associated with a lower risk of KSD. Among female diabetic patients, systolic blood pressure and HOMA2-B were both contributing factors, and ACEIs acted as a protective factor for KSD.

Conclusion

Among Chinese patients with T2DM, approximately 1 in 7 patients was affected by KSD, and the prevalence was twice as high as that in the general Chinese population. The factors associated with KSD varied by sex among T2DM patients. Focusing on these factors is beneficial for reducing the risk of KSD and delaying kidney damage in diabetic patients.

Association of simple renal cysts and chronic kidney disease with large abdominal aortic aneurysm

Background

Abdominal aortic aneurysms (AAA) primarily affect men over 65 years old who often have many other diseases, with similar risk factors and pathobiological mechanisms to AAA. The aim of this study was to assess the prevalence of simple renal cysts (SRC), chronic kidney disease (CKD), and other kidney diseases (e.g. nephrolithiasis) among patients presenting with AAA.

Methods

Two groups of patients (97 AAA and 100 controls), with and without AAA, from the Surgical Clinic Charité, Berlin, Germany, were selected for the study. The control group consisted of patients who were evaluated for a kidney donation (n = 14) and patients who were evaluated for an early detection of a melanoma recurrence (n = 86). The AAA and control groups were matched for age and sex. Medical records were analyzed and computed tomography scans were reviewed for the presence of SRC and nephrolithiasis.

Results

SRC (74% vs. 57%; p<0.016) and CKD (30% vs. 8%; p<0.001) were both more common among AAA than control group patients. On multivariate analysis, CKD, but not SRC, showed a strong association with AAA.

Conclusions

Knowledge about pathobiological mechanisms and association between CKD and AAA could provide better diagnostic and therapeutic approaches for these patients.

Simple Renal Cysts Are Associated With 24-Month Prognosis of Patients With Type B Aortic Dissection and Hypertension

BACKGROUND

The association of simple renal cyst (SRC) with type B aortic dissection (BAD) has recently been established. However, no studies have examined adverse events after BAD hospitalization among patients with SRC. In this study, we assessed the prognostic value of SRC in BAD patients with hypertension after thoracic endovascular aortic repair (TEVAR).

METHODS

We studied all BAD patients with hypertension who were admitted for TEVAR (n = 238; age 56.1 ± 9.8 years, 84.0% male). Aortic-related adverse events (ARAE) were evaluated as outcomes at 3 months and 24 months after TEVAR.

RESULTS

Among the total number of patients, 104 (43.7%) had at least 1 SRC. Patients with SRC were significantly older than those without (59.6 ± 8.8 vs 53.3 ± 9.7; P < 0.001). Patients with SRC were also more likely to suffer from peripheral arterial disease (55.8% vs 40.3%; P = 0.018) and cerebrovascular accidents (47.1% vs 29.9%; P = 0.006) than those without. Median follow-up for the 238 patients was 18.5 (range 6.4-24.0) months. Cumulative ARAE-free rates were 94.5 ± 1.5% at the 3-month follow-up and 81.5 ± 2.8% at the 24-month follow-up. Independent predictors of 3-month ARAE were found to be insertion of ≥ 2 stents (hazard ratio [HR] 3.977, 95% confidence interval [CI] 1.224-12.920; P = 0.022). For 24-month follow-up, SRC (HR 1.962, 95% CI 1.023-3.764; P = 0.043) was evaluated as the only independent predictive factor. SRC (HR 8.841, 95% CI 1.726-45.294; P = 0.009) was also evaluated as an independent predictive factor for 24-month ARAEs in the chronic group, but not in the acute or the subacute group.

CONCLUSIONS

SRC could predict 24-month ARAE in BAD patients with hypertension after TEVAR, especially in the chronic group.

Incidental Extraspinal Findings in the Thoracic Spine during Magnetic Resonance Imaging of Intervertebral Discs

Objective:

The purpose of this research was to determine the frequency of incidental extraspinal findings in the thoracic spine on magnetic resonance imaging (MRI).

Materials and Methods:

A total of 120 thoracic spine MRI patients were prospectively examined in the period extending from August 2018 to April 2019. Both 1.5 and 0.35 Tesla MRI systems (Toshiba and Siemens Medical system) were applied to investigate patients with suspected intervertebral disc abnormalities at three MRI diagnostic centers in Khartoum, Sudan.

Results:

Out of the 120 patients, incidental extraspinal findings were found in 16 patients (13.3%). Various incidental findings (IFs) were seen, including renal cysts, liver mass, thyroid goiter, and pleural effusion. Out of these IFs, 37.5% were considered clinically significant.

Conclusions:

Various IFs were identified during a routine thoracic spine MRI, and approximately one-third of them were clinically significant. Therefore, it is essential for the reporting radiologists to pay attention to extraspinal findings while reporting thoracic spine MRI to avoid missing clinically significant findings.

Chronic kidney disease in propionic acidemia

Purpose

Propionic acidemia (PA) is a severe metabolic disorder characterized by multiorgan pathology, including renal disease. The prevalence of chronic kidney disease (CKD) in PA patients and factors associated with CKD in PA are not known.

Methods

Thirty-one subjects diagnosed with PA underwent laboratory and clinical evaluations through a dedicated natural history study at the NIH (ClinicalTrials.gov identifier: NCT02890342).

Results

Cross-sectional analysis of the creatinine-based estimated glomerular filtration rate (eGFR) in subjects with native kidneys revealed an age-dependent decline in renal function (P <0.002). Among adults with PA, 4/8 (50%) had eGFR <60 mL/min/1.73 m². There was a significant discrepancy between eGFRs calculated using estimating equations based on serum creatinine compared to serum cystatin C (P <0.0001). The tubular injury marker, plasma lipocalin-2, and plasma uric acid were strongly associated with CKD (P <0.0001). The measured 24-hour creatinine excretion was below normal, even after adjusting for age, height, and sex.

Conclusions

CKD is common in adults with PA and is associated with age. The poor predictive performance of standard eGFR estimating equations, likely due to reduced creatine synthesis in kidney and liver, could delay the recognition of CKD and management of ensuing complications in this population.

Association between simple renal cyst and kidney damage in a Chinese cohort study

Background: The presence of simple renal cyst (SRC) has been associated to renal dysfunction, but the results were inconsistent. Accordingly, we conducted a longitudinal cohort study to explore the association between SRC and kidney damage.

Methods: A total of 4274 adults (aged 45.4 ± 13.6 years) without chronic kidney disease at baseline were enrolled in 2008. SRC was assessed by ultrasonography. Logistic regression analysis were applied to explore the relationships between SRC and indicators of kidney damage (proteinuria and renal insufficiency), and also with relatively rapid decline in renal function (defined as the lowest quartile of △eGFR).

Results: During 5 years of follow-up, participants in the SRC group had higher incidence of proteinuria (5.2% versus 2.4%, p = 0.004) and renal insufficiency (3.8% versus 0.97%, p < 0.001) compared with control group. SRC was correlated with proteinuria (OR 2.24; 95% CI 1.34–3.75) and renal insufficiency (OR 4.0; 95% CI 2.11–7.58) in univariable analysis, despite that the correlation was not significant after adjusted for traditional kidney disease risk factors. Furthermore, after adjusted for potential confounders, maximum diameter of the cyst (≥2.2 cm) was significantly associated with rapid decline in renal function (OR 2.19; 95% CI 1.24–3.87).

Conclusions: Participants with SRC may be associated with higher incidence of proteinuria and renal insufficiency. This relationship may be obscured by age and other traditional risk factors. Higher diameter of the cysts contributed to more rapid decline in renal function of SRC participants.

Prevalence of renal cysts and association with risk factors in a general population: an MRI-based study

PURPOSE

To assess the prevalence and size of renal cysts and to analyze associated risk factors in a general population using magnetic resonance imaging (MRI).

METHODS

Data of 2063 participants (1052 women) of the Study of Health in Pomerania who underwent whole-body MRI were included. Renal cyst prevalence was calculated separately for men and women and for 10-year age groups. The association between risk factors and occurrence of renal cysts was estimated.

RESULTS

The prevalence of renal cysts was 27% and higher in men (34%) than in women (21%; p < 0.001). Renal cyst prevalence increased from 14% in the youngest age group (20-29 years) to 55% in the oldest age group (≥ 70 years) for men and from 7% to 43% for women (both p < 0.001). In the subset of participants with renal cysts, the total mean number was higher in men (1.9) compared to women (1.6, p = 0.012) and was significantly associated with age. Mean renal cyst size was higher in men (1.50 cm) compared to women (1.18 cm, p < 0.001). Male sex (OR 1.83, 95% CI 1.47; 2.26), older age (OR 1.05, 95% CI 1.04; 1.06, per 1-year increment), and hypertension (OR 1.27, 95% CI 1.00; 1.61) were associated with higher renal cyst prevalence. In additional analyses, current smoking and ex-smoking showed a significantly higher risk for renal cysts (OR 1.47, 95% CI 1.05; 2.05 and OR 1.38, 95% CI 1.04; 1.82, respectively).

CONCLUSIONS

The prevalence, number, and mean size of renal cysts are higher in men compared to women and are associated with age. In addition, renal cyst prevalence is higher in hypertensive and smoking subjects.

Successful Laparoscopy-Assisted Resection of the Descending Colon in a Patient with Multiple Large Renal Cysts and Stricture of the Colon due to Ischemic Colitis

Large pathological structures in the abdominal cavity curb the application of laparoscopic surgery. This case report describes a successful laparoscopy-assisted colectomy for benign colon disease in a patient with multiple large renal cysts. An 82-year-old man was referred to our department for treatment of stenosis of descending colon secondary to ischemic colitis. An abdominal computed tomography revealed multiple large renal cysts occupying a large proportion of the peritoneal cavity. To minimize the postoperative recovery period, laparoscopic surgery was planned despite the renal cysts. After inserting access ports, the walls of the several renal cysts were fenestrated with an electronic scalpel and the serous fluid was aspirated to enable continuation of the laparoscopic colectomy. The left colon was mobilized and extracted through an incision at the umbilicus, and the affected part of the colon was resected safely. The patient's postoperative course was uneventful, and the present case suggests that laparoscopy-assisted colectomy can be performed safely even in patients with multiple large renal cysts.

Incidental extraspinal findings in the lumbar spine during magnetic resonance imaging of intervertebral discs

Purpose

To calculate the frequencies of incidental extraspinal findings and incidentally detected congenital anomalies or anatomical differences in the lumbar spine on magnetic resonance imaging (MRI) scans of intervertebral discs.

Materials and methods

A total of 379 lumbar spine MRI cases were prospectively investigated in the period spanning from August 2016 to January 2018. Both 1.5 and 0.35 Tesla MRI units (Toshiba and Siemens Medical Systems) were used to examine patients with clinically suspected intervertebral disc abnormalities at three MRI diagnostic centers in Khartoum State, Sudan.

Results

Of the 379(100%) patients, 90(23.7%) patients were presented with incidental findings. Among the incidental findings, 39(10.3%) were renal cysts, 10(2.6%) were retroverted uteri, 5(1.3%) were Nabothian cysts, 4(1.1%) were ovarian cysts, 10(2.6%) were uterine fibroids, 3(0.8%) were endometrial thickening, 11(2.9%) were indicative of hydronephrosis, 4(1.1%) were uncovered prostatic enlargement, 2(0.5%) were atrophic kidney, and 1(0.3%) each was of an ectopic kidney and bladder wall thickening, respectively.

Conclusions

A high percentage of extraspinal pathological findings were detected during MRI lumbar spine scans of intervertebral discs. Thus, it is important to be aware of the high percentage of patients who undergo further evaluation given the presence of unexpected findings, but for whom clinical confirmation of these abnormalities is not obtained.

Increased risk of kidney damage among Chinese adults with simple renal cyst

BACKGROUND

The presence of simple renal cyst (SRC) has been related to hypertension, the early and long-term allograft function, and aortic disease, but the relationship with kidney damage was still controversial. Accordingly, we conducted a large sample cross-sectional study to explore the association of SRC with indicators of kidney damage among Chinese adults.

METHODS

A total of 42,369 adults (aged 45.8 ± 13.67 years, 70.6% males) who visited the Health Checkup Clinic were consecutively enrolled. SRC was assessed by ultrasonography according to Bosniak category. Multiple regression models were applied to explore the relationships between SRC and indicators of kidney damage [proteinuria (dipstick urine protein ≥ 1+) and decreased estimated glomerular filtration rate (DeGFR) < 60 ml/min/1.73 m²].

RESULTS

Among all participants in the study, the prevalence of SRC was 10.5%. As a categorical outcome, participants with more 1 cyst and with 1 cyst had higher percentage of proteinuria [53 (5.3%) and 93 (2.7%) vs. 596 (1.6%), p < 0.001] and DeGFR [57 (5.7%) and 85 (2.5%) vs. 278 (0.7%), p < 0.001] compared with participants with no cyst. SRC significantly correlated with proteinuria [OR 1.59 (95% CI 1.30-1.95)] and DeGFR [OR 1.97 (95% CI 1.56-2.47)] after adjusting for potential confounders. Furthermore, the results also demonstrated that maximum diameter (per 1 cm increase), bilateral location, and multiple cysts significantly correlated with DeGFR in the multiple logistic regression analysis.

CONCLUSIONS

The study revealed that SRC significantly correlated with kidney damage and special attention should be paid among Chinese adults with SRC.

Randomized study of percutaneous ureteroscopic plasma column electrode decortication and laparoscopic decortication in managing simple renal cyst

Background

To assess the safety and efficacy of a novel technology referred to as percutaneous ureteroscopic plasma column electrode (PCE) by comparing laparoscopic decortication in the management of simple renal cyst (SRC).

Methods

Between March 2016 and June 2017, 53 patients with SRCs were randomized to divided into two groups, the PCE group (24 patients), or laparoscope group (29 patients). The operative time, blood loss, days of drainage, catheter, and hospital stay and complications were compared with the two groups. All patients were followed- up to 6 months after treatment.

Results

No patients had intraoperative complications such as hemopneumothorax, adjacent organ injury, infection or hemorrhage shock. In the PCE group and laparoscope group: the mean operation time was 34.1±8.2 vs. 58.4±16.7 min (P<0.05). The mean blood loss was 2.0±1.16 vs. 9.7±4.09 mL (P<0.05). The mean postoperative indwelling drainage tube time was 2.5±1.5 vs. 2.9±1.09 d (P>0.05). The mean intra-urethral indwelling catheter time was 2.1±0.88 vs. 2.0±1.15 d (P>0.05). The mean postoperative hospital stay was 3.0±1.7 vs. 3.7±1.53 (P>0.05). One patient in electrode group was suffered from rupture of the collecting system during the operation, and was treated by indwelling D-J stent. During follow up, no cysts recurrence was found.

Conclusions

Percutaneous ureteroscopic PCE decortication is a safe, minimally invasive and effective therapy to treat SRCs, with equal efficacy and advantages in shortening the operation time and reducing the amount of intraoperative bleeding compared with laparoscopic decortication.

Retrograde Intrarenal Surgery for Symptomatic Renal Sinus Cysts: Long-Term Results and Literature Review

INTRODUCTION

To report the long-term multicenter experience with retrograde intrarenal holmium-laser incision (RIR-HoLI) in the management of symptomatic renal sinus cysts (RSCs). In the literature, RIR-HoLI has been shown to be a safe and effective treatment, but there are only a few reports regarding long-term results and reproducibility of this procedure.

MATERIAL AND METHODS

From June 2010 to June 2015, 14 patients with symptomatic RSCs underwent RIR-HoLI. The mean age was 52.1 ± 11.28 years (range 28-77) and the mean cyst size was 53.2 ± 14.23 mm (range 35-90). In all cases, contrast-enhanced computer tomography (CT) showed compression of the renal pelvis by the cyst (no malignancy). Surgical outcome was assessed in terms of symptoms improvement (measured by Visual Analogue Scale [VAS] for pain) and renal ultrasound findings at 3-6-12 months postoperatively and then yearly. CT scan was carried out at 12 months follow-up.

RESULTS

RIR-HoLI was successful in all patients. The mean operative time was 47.8 ± 13.54 min (range 30-80) and mean hospital stay was 3.5 days (range 2-5). There were 2 Clavien grade II complications (flank pain and urgency delaying discharge). After surgery, all patients -became asymptomatic (VAS score change, p = 0.0001). One patient had persistence of a small cyst (10 mm). Mean follow-up is 44 ± 17.24 months (range 24-84); all patients remained asymptomatic, with no signs of recurrence.

CONCLUSIONS

RIR-HoLI proved to be a safe and effective treatment for symptomatic RSCs. In our experience, it provided excellent long-term results and was reproducible at 4 different -institutions.

Radiologic Pearls for Internists: A Case-Based Review

Modern technologic advances in medical imaging and the increasing use of imaging across all disciplines in medicine have led to a striking rise in incidental findings unrelated to the original study indication. Often, these findings have no clinical relevance and will not impact the current or future health status of the patient. It is incumbent on radiologists to report these findings in a definitive and unambiguous manner. Similarly, it is essential for clinicians to restrain from further diagnostic investigation of incidental findings that are conclusive by imaging. A classic and common example is the finding of a cyst. This article presents several cases of incidentally found cysts for which a confident diagnosis can be made without any need for follow-up.

Association between renal cysts and abdominal aortic aneurysm: A case-control study

Summary Objective: To investigate the positive association between the presence of simple renal cysts (SRCs) and abdominal aortic aneurysm (AAA). Method: In a retrospective case-control study including subjects aged > 50 years, we evaluated the incidence of SRCs on computed tomography (CT) scan. We compared 91 consecutive patients with AAA referred from the Division of Vascular Surgery and 396 patients without AAA, randomly selected after being matched by age and gender from 3,186 consecutive patients who underwent abdominal CT. SRC was defined as a round or oval low-attenuation lesion with a thin wall and size > 4 mm on CT without obvious evidence of radiographic enhancement or septations. Patients were considered as having AAA if the size of aorta was greater than 3.0 cm. Results: Patients with AAA and without AAA were similar in terms of age (67.9± 8.41 vs. 68.5±9.13 years) (p=0.889) and gender (71.4 vs. 71.2% of male subjects, respectively) (p=0.999). There was no difference in the prevalence of SRC between case and controls. Among individuals with AAA, 38 (41.8%; [95CI 32.5-52.6]) had renal cysts compared to 148 (37.4%; [95CI 32.7-42.2]) in the control group (p=0.473), with a prevalence ratio (PR) of 1.16 (95CI 0.80-1.68). Conclusion: We found no significant differences in the prevalence of SRCs among patients with AAA and controls. Our findings suggest that the presence of SRCs is not a risk factor or a marker for AAA.

Algorithm for Bosniak 2F Cyst in Kidney Donation

Patient: Female, 54

Final Diagnosis: Multilocular cystic renal cell carcinoma with clear cells

Symptoms: None

Medication: —

Clinical Procedure: Hand-assisted retroperitoneal donor nephrectomy

Specialty: Transplantology

Hyperuricemia and overexcretion of uric acid increase the risk of simple renal cysts in type 2 diabetes

Previous studies have discussed the relationship between simple renal cysts (SRC) and serum uric acid level in healthy individuals. We performed a cross-sectional study to evaluate the association between serum uric acid level and fractional excretion of uric acid (FEUA) and simple renal cysts in males and postmenopausal females with type 2 diabetes. The overall prevalence of SRC was 18.1% in our population. SRC prevalence was significantly higher in hyperuricemic than normouricemic subjects (27.3% vs. 16.8%, P < 0.001). Subjects who overexcreted uric acid had a higher prevalence of SRC than underexcretors (total population: 21.6% vs. 16.3%; normouricemic subjects: 19.8% vs. 13.7%; hyperuricemic subjects: 50.0% vs. 22.7%, all P-values < 0.05). Hyperuricemia (odds ratio [OR] 1.824, 95% confidence interval [CI] 1.332-2.498, P < 0.001); FEUA (OR 1.046, 95% CI 1.002-1.091, P < 0.05); male gender (OR 1.922, 95% CI 1.489-2.480, P < 0.001); age (OR 1.049, 95% CI 1.035-1.064, P < 0.001); and albuminuria (OR 1.492, 95% CI 1.176-1.892, P < 0.01) were independent risk factors for SRC development. These findings suggested that hyperuricemia and high level of FEUA were both independent risk factors for SRC development in males and postmenopausal females with type 2 diabetes. Half of overproduction hyperuricemic patients had SRC.

Imaging of Renal Medullary Carcinoma

Renal medullary carcinoma (RMC) is a rare, highly aggressive tumor recognized as an independent pathological entity. African-descent adolescents and young adults with sickle cell hemoglobinopathy are the most affected groups. This rare subtype of renal cell carcinoma has its own morphogenetic and pathological characteristics. The major clinical manifestations include gross hematuria, abdominal or flank pain, and weight loss. The prognosis is very poor, with 95% of cases diagnosed at an advanced stage of the disease. In this review, we summarize the morphologic and dynamic characteristics of RMC under various imaging modalities such as ultrasound, computed tomography, and magnetic resonance. Differential diagnosis and management strategies are also discussed.

Prospective comparison of use of contrast-enhanced ultrasound and contrast-enhanced computed tomography in the Bosniak classification of complex renal cysts

AIM

To compare contrast-enhanced ultrasound and contrast-enhanced computed tomography in the evaluation of complex renal cysts using the Bosniak classification.

METHODS

Forty-six patients with 51 complex renal cysts were prospectively examined using contrast-enhanced ultrasound and contrast-enhanced computed tomography and images analysed by two observers using the Bosniak classification. Adverse effects and patients' preference were assessed for both modalities.

RESULTS

There was complete agreement in Bosniak classification between both modalities and both observers in six cysts (11.8%). There was agreement of Bosniak classification on both modalities in 21 of 51 cysts (41.2%) for observer 1 and in 17 of 51 cysts (33.3%) for observer 2. Contrast-enhanced ultrasound gave a higher Bosniak classification than corresponding contrast-enhanced computed tomography in 31 % of cysts by both observers. Histological correlation was available in three lesions, all of which were malignant and classified as such simultaneously on both modalities by at least one observer, with remaining patients followed up with US or CT for 6-24 months. No adverse or side effects were reported following the use of US contrast, whilst 63.6% of patients suffered minor side effects following the use of CT contrast. 81.8% of the surveyed patients preferred contrast-enhanced ultrasound to contrast-enhanced computed tomography.

CONCLUSION

Contrast-enhanced ultrasound is a feasible tool in the evaluation of complex renal cysts in a non-specialist setting. Increased contrast-enhanced ultrasound sensitivity to enhancement compared to contrast-enhanced computed tomography, resulting in upgrading the Bosniak classification on contrast-enhanced ultrasound, has played a role in at best moderate agreement recorded by the observers with limited experience, but this would be overcome as the experience grows. To this end, we propose a standardised proforma for the contrast-enhanced ultrasound report. The benefits of contrast-enhanced ultrasound over contrast-enhanced computed tomography include patients' preference and avoidance of ionising radiation or nephrotoxicity, as well as lower cost.

Simple Renal Cysts as Markers of Thoracic Aortic Disease

Background

Thoracic aortic aneurysm is usually a clinically silent disease; timely detection is largely dependent upon identification of clinical markers of thoracic aortic disease (TAD); (bicuspid aortic valve, intracranial aortic aneurysm, bovine aortic arch, or positive family history). Recently, an association of simple renal cysts (SRC) with abdominal aortic aneurysm and aortic dissection was established. The aim of our study was to evaluate the prevalence of SRC in patients with TAD in order to assess whether the presence of SRC can be used as a predictor of TAD.

Methods and Results

We evaluated the prevalence of SRC in 842 patients with TAD (64.0% males) treated at our institution from 2004 to 2013 and compared to a control group of patients (n=543; 56.2% males). Patients were divided into 4 groups: ascending aortic aneurysm (456; 54.2%); descending aortic aneurysm (86; 10.2%); type A aortic dissection (118; 14.0%); and type B aortic dissection (182; 21.6%). SRC were identified by abdominal computed tomography or magnetic resonance imaging of these patients. Prevalence of SRC is 37.5%, 57.0%, 44.1%, and 47.3% for patients with ascending aneurysm, descending aneurysm, type A dissection, and type B dissection, respectively. Prevalence of SRC in the control group was 15.3%. Prevalence of SRC was not significantly different between male and female aortic disease patients, despite reported general male predominance (2:1), which was also observed in our control group (1.7:1).

Conclusions

This study establishes an increased prevalence of SRC in patients with TAD. SRC can potentially be used as a marker for timely detection of patients at risk of TAD.

Prevalence of Simple Renal Cysts in Acromegaly

Objective Various organs are known to be affected by the comorbidities of acromegaly. However, the involvement of renal structural comorbidities, such as cysts, has so far remained largely unknown. In this single-center study, we aimed to determine the prevalence and factors associated with simple renal cysts in Japanese patients with acromegaly. Methods A total of 71 consecutive patients with acromegaly were analyzed, who all underwent abdominal ultrasonography at diagnosis between 1986 and 2012 at Kobe University Hospital. Results Of these 71 patients, 23 (32.4%) exhibited simple renal cysts. Acromegalic patients with renal cysts tended to be significantly older, had a higher prevalence of smoking- and higher nadir growth hormone (GH) levels during the oral glucose tolerance test (OGTT) than did those without renal cysts. A multivariate logistic regression analysis showed age, smoking, and nadir GH to be independent factors associated with renal cysts. Interestingly, the number of renal cysts positively correlated with both the basal GH levels and nadir GH levels during OGTT (r=0.66, p<0.05 and r=0.70, p<0.05, respectively). In addition, the mean diameter of renal cysts positively correlated with the systolic blood pressure (r=0.84, p<0.005). Conclusion This is the first report to show the prevalence of simple renal cysts in patients with acromegaly. Elevated nadir GH levels during OGTT were found to be associated with an increased risk of simple renal cysts. Therefore, an excessive secretion of GH may be related to the development of renal cysts.