Activation of farnesoid X receptor retards expansion of renal collecting duct cell-derived cysts via inhibition of CFTR-mediated Cl- secretion.

The transcription factor farnesoid X receptor (FXR) regulates energy metabolism. Specifically, FXR functions to regulate cystic fibrosis transmembrane conductance regulator (CFTR)-mediated Cl- secretion in intestinal epithelial cells. Therefore, this study aimed to investigate the role of FXR in CFTR-mediated Cl- secretion in renal tubular cells and to further elucidate its effects on renal cyst formation and growth. CFTR-mediated Cl- transport was evaluated via short-circuit current (ISC) measurements in Madin-Darby canine kidney (MDCK) cell monolayers and primary rat inner medullary collecting duct cells. The role of FXR in renal cyst formation and growth was determined by the MDCK cell-derived cyst model. Incubation with synthesized (GW4064) and endogenous (CDCA) FXR ligands reduced CFTR-mediated Cl- secretion in a concentration- and time-dependent manner. The inhibitory effect of FXR ligands was not due to the result of reduced cell viability and was attenuated by cotreatment with an FXR antagonist. FXR activation significantly decreased CFTR protein but not its mRNA. In addition, FXR activation inhibited CFTR-mediated Cl- secretion in primary renal collecting duct cells. FXR activation decreased ouabain-sensitive ISC without altering Na+-K+-ATPase mRNA and protein levels. Furthermore, FXR activation significantly reduced the number of cysts and renal cyst expansion. These inhibitory effects were correlated with a decrease in the expression of protein synthesis regulators mammalian target of rapamycin/S6 kinase. This study shows that FXR activation inhibits Cl- secretion in renal cells via inhibition of CFTR expression and retards renal cyst formation and growth. The discoveries point to a physiological role of FXR in the regulation of CFTR and a potential therapeutic application in polycystic kidney disease treatment.NEW & NOTEWORTHY The present study reveals that farnesoid X receptor (FXR) activation reduces microcyst formation and enlargement. This inhibitory effect of FXR activation is involved with decreased cell proliferation and cystic fibrosis transmembrane conductance regulator-mediated Cl- secretion in renal collecting duct cells. FXR might represent a novel target for the treatment of autosomal dominant polycystic kidney disease.

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.

Incidental Renal Cysts Found by Point-of-Care Ultrasound: A Retrospective Chart Review.

BACKGROUND: Incidental findings are unrelated to a patient's complaint, found on diagnostic imaging, such as point-of-care ultrasound (POCUS). Incidental findings represent potential harms to patients and may lead to increased patient anxiety and health care costs related to downstream testing and surveillance. STUDY OBJECTIVES: In this study, we aimed to calculate the rate of incidental renal cysts found by POCUS. Further, we hoped to describe how emergency physicians relay the findings to patients. Lastly, we hoped to examine if patients suffered harms in the 12 months following identification of an incidental renal cyst. METHODS: From our single-center, academic emergency department (ED), we reviewed renal POCUS images from 1000 consecutive adult ED patients to determine if there was a renal cyst. Next, we performed manual chart review to determine if patients were informed of the incidental renal cyst or suffered any patient harms. RESULTS: We found the prevalence of renal cysts to be 6.5% (95% confidence interval: 4.9%-8.4%). Those with cysts were more likely to be older compared to those without (63 ± 14 vs. 49 ± 15 years of age). Only 8% of patients had evidence that they were informed of their incidental renal cyst. No patients received a biopsy or were diagnosed with renal cell carcinoma or polycystic kidney disease. CONCLUSION: Incidental renal cysts are common and are more likely to be found in older adults. In our study, physicians infrequently informed patients of their incidental finding.

Diagnosis and Surgical Treatment of a Renal Cyst Causing Unilateral Lameness in a Golden Eagle (Aquila chrysaetos).

This report describes the diagnosis and treatment of a benign renal cyst in an adult, female golden eagle (Aquila chrysaetos) presented for unilateral leg lameness. A cyst at the cranial division of the left kidney was diagnosed by computed tomography and was suspected of compressing the lumbosacral nerve plexus, resulting in limb lameness. The renal cyst was incompletely excised because the cyst wall was closely adhered to the kidney parenchyma and local blood supply. Fluid analysis and surgical biopsy of the cyst and left kidney confirmed the diagnosis of a benign renal cyst. No evidence of an infectious, inflammatory, or neoplastic etiology was noted. Postoperatively, the eagle's lameness resolved and the bird was ultimately released following recovery. During treatment for the renal cyst, the eagle was concurrently found to have increased serum titers on elementary body agglutination for Chlamydia psittaci and a positive titer for Aspergillus species antibody testing. The bird was administered doxycycline, azithromycin, and voriconazole for treatment of these potential pathogens prior to release. Unfortunately, the eagle was found dead 86 days postrelease due to an unknown cause. To the authors' knowledge, this is the first report of a golden eagle with a benign solitary renal cyst causing unilateral lameness secondary to nerve compression that was resolved with surgical excision.

Ouabain enhances renal cyst growth in a slowly progressive mouse model of autosomal dominant polycystic kidney disease.

Renal cyst progression in autosomal dominant polycystic kidney disease (ADPKD) is highly dependent on agents circulating in blood. We have previously shown, using different in vitro models, that one of these agents is the hormone ouabain. By binding to Na+-K+-ATPase (NKA), ouabain triggers a cascade of signal transduction events that enhance ADPKD cyst progression by stimulating cell proliferation, fluid secretion, and dedifferentiation of the renal tubular epithelial cells. Here, we determined the effects of ouabain in vivo. We show that daily administration of ouabain to Pkd1RC/RC ADPKD mice for 1-5 mo, at physiological levels, augmented kidney cyst area and number compared with saline-injected controls. Also, ouabain favored renal fibrosis; however, renal function was not significantly altered as determined by blood urea nitrogen levels. Ouabain did not have a sex preferential effect, with male and female mice being affected equally. By contrast, ouabain had no significant effect on wild-type mice. In addition, the actions of ouabain on Pkd1RC/RC mice were exacerbated when another mutation that increased the affinity of NKA for ouabain was introduced to the mice (Pkd1RC/RCNKAα1OS/OS mice). Altogether, this work highlights the role of ouabain as a procystogenic factor in the development of ADPKD in vivo, that the ouabain affinity site on NKA is critical for this effect, and that circulating ouabain is an epigenetic factor that worsens the ADPKD phenotype.NEW & NOTEWORTHY This work shows that the hormone ouabain enhances the progression of autosomal dominant polycystic kidney disease (ADPKD) in vivo. Ouabain augments the size and number of renal cysts, the kidney weight to body weight ratio, and kidney fibrosis in an ADPKD mouse model. The Na+-K+-ATPase affinity for ouabain plays a critical role in these effects. In addition, these outcomes are independent of the sex of the mice.

Individuals heterozygous for ALG8 protein-truncating variants are at increased risk of a mild cystic kidney disease.

ALG8 protein-truncating variants (PTVs) have previously been described in patients with polycystic liver disease and in some cases cystic kidney disease. Given a lack of well-controlled studies, we determined whether individuals heterozygous for ALG8 PTVs are at increased risk of cystic kidney disease in a large, unselected health system-based observational cohort linked to electronic health records in Pennsylvania (Geisinger-Regeneron DiscovEHR MyCode study). Out of 174,172 patients, 236 were identified with ALG8 PTVs. Using ICD-based outcomes, patients with these variants were significantly at increased risk of having any kidney/liver cyst diagnosis (Odds Ratio 2.42, 95% confidence interval: 1.53-3.85), cystic kidney disease (3.03, 1.26-7.31), and nephrolithiasis (1.89, 1.96-2.97). To confirm this finding, blinded radiology review of computed tomography and magnetic resonance imaging studies was completed in a matched cohort of 52 thirty-plus year old ALG8 PTV heterozygotes and related non-heterozygotes. ALG8 PTV heterozygotes were significantly more likely to have cystic kidney disease, defined as four or more kidney cysts (57.7% vs. 7.7%), or bilateral kidney cysts (69.2% vs. 15.4%), but not one or more liver cyst (11.5% vs. 7.7%). In publicly available UK Biobank data, ALG8 PTV heterozygotes were at significantly increased risk of ICD code N28 (other disorders of kidney/ureter) (3.85% vs. 1.33%). ALG8 PTVs were not associated with chronic kidney disease or kidney failure in the MyCode study or the UK Biobank data. Thus, PTVs in ALG8 result in increased risk of a mild cystic kidney disease phenotype.

Association of simple renal cysts to aneurysm sac shrinkage in true thoracic aortic aneurysms after thoracic endovascular aortic repair.

BACKGROUND: An increased prevalence of thoracic aortic aneurysms (TAA) has been demonstrated in patients with simple renal cysts (SRC); patients with SRC have a less elastic aortic wall than those without SRC. The purpose of this study was to evaluate aneurysm sac shrinkage after thoracic endovascular aortic repair (TEVAR) for true TAA in patients with and without SRC. METHODS: One hundred three patients with true aneurysms of the thoracic aorta who underwent TEVAR at our university hospital from November 2013 to December 2021 were included in this study. Aneurysm sac size was compared between that on baseline preoperative computed tomography and that on postoperative computed tomography scans at 1 year. A change in aneurysm sac size ≥5 mm was considered to be significant, whether due to expansion or shrinkage. RESULTS: The patients were divided into two groups: those with SRC (46 patients [45%]) and those without SRC (57 patients [55%]). At 1 year, there was a significant difference in the proportion of aneurysm sac shrinkage between patients with SRC and those without SRC (23.9% vs 59.6%; P < .001). Patients with SRC showed significantly less aneurysm sac shrinkage than those without SRC (-1.8 ± 5.6 mm vs -5.1 ± 6.6 mm; P = .009). Univariable and multivariable analyses showed that the initial sac diameter (odds ratio, 1.08; 95% confidence interval, 1.03-1.14; P = .002) and the presence of SRC (odds ratio, 0.15; 95% confidence interval, 0.06-0.40; P < .001) were positively and negatively associated with aneurysm sac shrinkage after TEVAR, respectively. CONCLUSIONS: The presence of a SRC was independently associated with failure of aneurysm sac shrinkage after TEVAR for true TAA. This suggests that the presence of a SRC may be a predictor for the failure of aneurysm sac shrinkage after TEVAR.

Ultrasound-based "CEUS-Bosniak"classification for cystic renal lesions: an 8-year clinical experience.

PURPOSE: Renal cysts comprise benign and malignant entities. Risk assessment profits from CT/MRI imaging using the Bosniak classification. While Bosniak-IIF, -III, and -IV cover complex cyst variants, Bosniak-IIF and -III stand out due to notorious overestimation. Contrast-enhanced ultrasound (CEUS) is promising to overcome this deficit but warrants standardization. This study addresses the benefits of a combined CEUS and CT/MRI evaluation of renal cysts. The study provides a realistic account of kidney tumor boards' intricacies in trying to validate renal cysts. METHODS: 247 patients were examined over 8 years. CEUS lesions were graded according to CEUS-Bosniak (IIF, III, IV). 55 lesions were resected, CEUS-Bosniak- and CT/MRI-Bosniak-classification were correlated with histopathological diagnosis. Interobserver agreement between the classifications was evaluated statistically. 105 lesions were followed by ultrasound, and change in CEUS-Bosniak-types and lesion size were documented. RESULTS: 146 patients (156 lesions) were included. CEUS classified 67 lesions as CEUS-Bosniak-IIF, 44 as CEUS-Bosniak-III, and 45 as CEUS-Bosniak-IV. Histopathology of 55 resected lesions revealed benign cysts in all CEUS-Bosniak-IIF lesions (2/2), 40% of CEUS-Bosniak-III and 8% of CEUS-Bosniak-IV, whereas malignancy was uncovered in 60% of CEUS-Bosniak-III and 92% of CEUS-Bosniak-IV. Overall, CEUS-Bosniak-types matched CT/MRI-Bosniak types in 58% (fair agreement, κ = 0.28). CEUS-Bosniak resulted in higher stages than CT/MRI-Bosniak (40%). Ultrasound follow-up of 105 lesions detected no relevant differences between CEUS-Bosniak-types concerning cysts size. 99% of lesions showed the same CEUS-Bosniak-type. CONCLUSION: The CEUS-Bosniak classification is an essential tool in clinical practice to differentiate and monitor renal cystic lesions and empowers diagnostic work-up and patient care.

Large deletion of Wdr19 in developing renal tubules disrupts primary ciliogenesis, leading to polycystic kidney disease in mice.

WD repeat domain 19 (Wdr19) is a major component of the intraflagellar transport (IFT) machinery, which is involved in the function of primary cilia. However, the effects of Wdr19 on primary cilia formation, cystogenesis, and polycystic kidney disease (PKD) progression remain unclear. To study these effects, we generated three lines of kidney-specific conditional knockout mice: Wdr19-knockout (Wdr19-KO, Wdr19f/- ::Cdh16-CreTg/0 ), Pkd1-knockout (Pkd1-KO, Pkd1f/- ::Cdh16-CreTg/0 ), and Wdr19/Pkd1-double knockout (Wdr19&Pkd1-dKO, Wdr19f/- ;Pkd1f/- ::Cdh16-CreTg/0 ) mice. Ultrastructural analysis using transmission electron microscopy (TEM) indicated that the primary cilia were almost absent at postnatal day 10 in Wdr19-KO mice compared with Pkd1-KO and wild-type (WT) mice. However, the primary cilia appeared structurally normal even if malfunctional in Pkd1-deficient cysts. The Pkd1-KO mice had the most severe PKD progression, including the shortest lifespan (14 days) and the largest renal cysts, among the three knockout lines. Thus, the molecular mechanism of renal cystogenesis in Wdr19-KO mice (primary cilia abrogation) was different from that in Pkd1-KO mice (primary cilia malfunction). In summary, Wdr19 deficiency leads to primary cilia abrogation and renal cyst formation. Wdr19 is primarily proposed to participate in retrograde IFT and to be crucial for the construction of primary cilia, which are critical organelles for tubulogenesis in the developing kidneys. © 2022 The Pathological Society of Great Britain and Ireland.

Cystic kidney disease in tuberous sclerosis complex: current knowledge and unresolved questions.

Tuberous sclerosis complex (TSC) is an autosomal dominant disorder with an estimated incidence of one in 5000 to 10,000 live births worldwide. Two million people of all races and genders are estimated to have TSC secondary to mutations in one of two tumor suppressor genes, TSC1 or TSC2. The respective TSC1 and 2 gene products - hamartin and tuberin - form cytoplasmic heterodimers that inhibit mTOR-mediated cell growth and division. When mTOR inhibition is lost, people with TSC develop characteristic and usually benign tumors in various organ systems. Kidney tumors and cysts are common, particularly in the setting of TSC2 gene mutations. In most TSC patients, the number of kidney cysts is limited, their morphology is simple, their size is small, and their clinical significance is negligible. In some, cyst morphology progresses from simple to complex with the risk of malignant transformation. In others, aggressive accumulation and growth of kidney cysts can cause hypertension, impaired kidney function, and progression to kidney failure. This educational review summarizes current knowledge and remaining open questions regarding cystic kidney disease in TSC, emphasizing detection, classification, surveillance, and treatment options.

[Effect of a simple kidney cyst on renal function].

INTRODUCTION: Renal cysts are a common disease that occurs at a rate of 7-10%. Currently there are no clinical recommendations for the treatment of patients with simple renal cysts. In the current literature there is some evidence that a simple renal cyst has negative effects on renal function. Decreased renal function occurs due to partial atrophy and loss of the renal parenchyma (in the "crater" area at the base of the cyst) caused by compression. Therefore, the efforts to analyze the effect of simple kidney cysts on kidney function and identify the characteristics of the cyst that affect renal function to determine the indications for surgical treatment remains a substantial task. The aim of the study was to analyze the effect of simple renal cysts on renal function, to investigate the relationship between cyst size, atrophied parenchyma volume, and renal function, and to determine indications for surgical treatment of simple renal cysts. MATERIALS AND METHODS: We conducted a prospective cohort study. The study included 109 patients with simple renal cysts. Patients with a solitary cyst of the right or left renal kidney, grade I-II according to Bosniak classification, were included in the study. The estimated glomerular filtration rate (eGFR) of the patients was calculated using various formulas. A contrast CT scan of the urinary tract was also performed to determine the maximum size of the cyst, calculate the volume of the renal parenchyma, and the volume of the lost (atrophied) parenchyma. Patients underwent renal scintigraphy with calculation of total GFR and split renal function. We analyzed the symmetry of the function of both kidneys by comparing the GFR of the affected and healthy kidneys, analyzed the relationship between the presence of a kidney cyst and a decrease in GFR, between the maximum size of a renal cyst and a decrease in its function compared with that of a healthy kidney. We also analyzed the correspondence of total GFR values obtained in renal scintigraphy and GFR values calculated according to the formulas. RESULTS: Data from 109 patients were available for analysis; the mean blood creatinine was 87.4 mol/L. The median maximum cyst size was 80 mm. The median baseline volume of the affected kidney parenchyma was 174 ml, the median volume of the lost parenchyma was 49 ml, and the median proportion of the lost parenchyma was 28%. The median total GFR was 77.07 ml/min. The median GFR of the healthy kidney was 45.49 mL/min, and the median GFR of the kidney affected by the cyst was 34.46 mL/min. The median difference in GFR of the healthy and affected kidney units was 11 mL/min and was statistically significant. Comparison of the eGFR values obtained by the formulas with the reference values of GFR obtained by scintigraphy showed that the Cockcroft-Gault formula with standardization on the body surface area calculated closest eGFR values to the reference ones. Correlation analysis revealed a statistically significant association between the proportion of lost parenchyma volume and the maximum cyst size: =0.37 with 95% CI [0.20; 0.52] (p-value = 0). A multivariate logistic regression model revealed that a statistically significant factor influencing the probability of a significant decrease in GFR was the percent of lost renal parenchyma volume (OR=1,13; =0). CONCLUSIONS: Our study showed that growth of renal cysts associated with renal parenchyma atrophy and decrease of GFR of the affected kidney. An increase in the volume of atrophied parenchyma leads to the decrease in GFR of the affected kidney. The obtained data suggest that performing dynamic renal scintigraphy to assess the decrease in affected renal function and determine the indications for surgical treatment of renal cysts is a reasonable recommendation. According to the results of the study, the loss of 20% of the renal parenchyma can be considered an indication for renal scintigraphy. The Cockcroft-Gault formula with standardization on the body surface area allows to calculate closest GFR values to those obtained by scintigraphy and, therefore, can be recommended as the optimal formula for calculating eGFR in daily clinical practice.

Mutations in NCAPG2 Cause a Severe Neurodevelopmental Syndrome that Expands the Phenotypic Spectrum of Condensinopathies.

The use of whole-exome and whole-genome sequencing has been a catalyst for a genotype-first approach to diagnostics. Under this paradigm, we have implemented systematic sequencing of neonates and young children with a suspected genetic disorder. Here, we report on two families with recessive mutations in NCAPG2 and overlapping clinical phenotypes that include severe neurodevelopmental defects, failure to thrive, ocular abnormalities, and defects in urogenital and limb morphogenesis. NCAPG2 encodes a member of the condensin II complex, necessary for the condensation of chromosomes prior to cell division. Consistent with a causal role for NCAPG2, we found abnormal chromosome condensation, augmented anaphase chromatin-bridge formation, and micronuclei in daughter cells of proband skin fibroblasts. To test the functional relevance of the discovered variants, we generated an ncapg2 zebrafish model. Morphants displayed clinically relevant phenotypes, such as renal anomalies, microcephaly, and concomitant increases in apoptosis and altered mitotic progression. These could be rescued by wild-type but not mutant human NCAPG2 mRNA and were recapitulated in CRISPR-Cas9 F0 mutants. Finally, we noted that the individual with a complex urogenital defect also harbored a heterozygous NPHP1 deletion, a common contributor to nephronophthisis. To test whether sensitization at the NPHP1 locus might contribute to a more severe renal phenotype, we co-suppressed nphp1 and ncapg2, which resulted in significantly more dysplastic renal tubules in zebrafish larvae. Together, our data suggest that impaired function of NCAPG2 results in a severe condensinopathy, and they highlight the potential utility of examining candidate pathogenic lesions beyond the primary disease locus.

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.

First case of a renal cyst infection caused by Desulfovibrio: a case report and literature review.

BACKGROUND: Genus Desulfovibrio species is a sulphate-reducing anaerobic gram-negative rod that resides in the human oral cavity and intestinal tract. It was reported as the causative pathogen of bacteraemia and abdominal infections, but not renal cyst infection, and Desulfovibrio fairfieldensis has higher pathogenicity than other Desulfovibrio species. CASE PRESENTATION: A 63-year-old man was on haemodialysis for end-stage renal failure due to autosomal dominant polycystic kidney disease. On admission, he had a persistent high-grade fever, right lumbar back pain, and elevated C-reactive protein levels. His blood and urine cultures were negative. He received ciprofloxacin and meropenem; however, there was no clinical improvement. Contrast-enhanced computed tomography and plain magnetic resonance imaging revealed a haemorrhagic cyst at the upper pole of the right kidney. The lesion was drained. Although the drainage fluid culture was negative, D. fairfieldensis was detected in a renal cyst using a polymerase chain reaction. After the renal cyst drainage, he was treated with oral metronidazole and improved without any relapse. CONCLUSIONS: To the best of our knowledge, this is the first reported case of a renal cyst infection with Desulfovibrio species. D. fairfieldensis is difficult to detect, and polymerase chain reaction tests can detect this bacterium and ensure better management for a successful recovery.

A case report of renal calyceal diverticulum with hypertension in children and review of literature.

BACKGROUND: Renal calyx diverticulum refers to a cystic lesion covered with the transitional epithelium in the renal parenchyma. Although there is no clear evidence that calyx diverticulum can cause hypertension, there exists a close association between the two, and there are few related reports. Herein, we reported the case of a child with renal calyx diverticulum complicated with hypertension and summarized the diagnosis and treatment. CASE PRESENTATION: Physical examination of the patient, an 11-year-old child, revealed a left renal cyst with hypertension (155/116 mmHg). There were no related symptoms. Routine urine and blood biochemical examinations showed no abnormalities. Imaging revealed left renal cyst compression causing the hypertension. She underwent renal cyst fluid aspiration and injection of a sclerosing agent into the capsule, but her blood pressure increased again 3 days postoperatively. Color Doppler ultrasonography showed that the size of the left renal cyst was the same as that preoperatively. To further confirm the diagnosis, cystoscopic retrograde ureteropyelography was performed to confirm the diagnosis of renal calyx diverticulum. Subsequently, renal calyceal diverticulum resection and calyx neck enlargement were performed. The operation went smoothly and the blood pressure returned to normal postoperatively. No abnormalities were noted at the 7-month postoperative follow-up. CONCLUSION: There exists an association between renal calyx diverticulum and hypertension. Therefore, hypertension can be considered a surgical indication for renal calyx diverticulum. Moreover, renal calyceal diverticulum in children can be easily misdiagnosed as a renal cyst. Therefore, it is important to be vigilant to prevent a series of complications, such as postoperative urine leakage, in such cases.

Calyceal diverticula: Clinical, radiological and histopathological findings of an uncommon entity with presumed congenital origin.

Calyceal diverticula (CD) are relatively uncommon urologic conditions that generally follow an asymptomatic course and rarely require medical intervention. CD are thought to have a congenital origin due to abnormalities during the process of ureteral bud formation. Clinically and radiologically, they can mimic multiple neoplastic and non-neoplastic renal processes, with potentially relevant differences in the management of these patients. Symptoms are usually associated with the presence of stones, obstruction to the drainage of the diverticulum, large size, or secondary infection. In chronic cases, surgery might become necessary, creating an opportunity to examine the histopathological characteristics of this condition. Although these are benign in the majority of patients, some rare instances of malignancy arising from the CD have been reported. In this series, we addressed the clinical, radiological, and histopathological findings of CD.

Update on MRI of Cystic Renal Masses Including Bosniak Version 2019.

Incidental cystic renal masses are common, usually benign, and almost always indolent. Since 1986, the Bosniak classification has been used to express the risk of malignancy in a cystic renal mass detected at imaging. Historically, magnetic resonance imaging (MRI) was not included in that classification. The proposed Bosniak v.2019 update has formally incorporated MRI, included definitions of imaging terms designed to improve interobserver agreement and specificity for malignancy, and incorporated a variety of masses that were incompletely defined or not included in the original classification. For example, at unenhanced MRI, homogeneous masses markedly hyperintense at T2 -weighted imaging (similar to cerebrospinal fluid) and homogeneous masses markedly hyperintense at fat suppressed T1 -weighted imaging (approximately ≥2.5 times more intense than adjacent renal parenchyma) are classified as Bosniak II and may be safely ignored, even when they have not been imaged with a complete renal mass MRI protocol. MRI has specific advantages and is recommended to evaluate masses that at computed tomography (CT) 1) have abundant thick or nodular calcifications; 2) are homogeneous, hyperattenuating, ≥3 cm, and nonenhancing; or 3) are heterogeneous and nonenhancing. Although MRI is generally excellent for characterizing cystic renal masses, there are unique weaknesses of MRI that bear consideration. These details and others related to MRI of cystic renal masses are described in this review, with an emphasis on Bosniak v.2019. A website (https://bosniak-calculator.herokuapp.com/) and mobile phone apps named "Bosniak Calculator" have been developed for ease of assignment of Bosniak classes. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY STAGE: 3.

Bosniak Classification of Cystic Renal Masses Version 2019: Comparison With Version 2005 for Class Distribution, Diagnostic Performance, and Interreader Agreement Using CT and MRI.

BACKGROUND. The Bosniak classification system for cystic renal masses (CRMs) was updated in 2019, requiring further investigation. OBJECTIVE. The purpose of this study was to compare versions 2005 and 2019 of the Bosniak classification system in terms of class distribution, diagnostic performance, interreader agreement, and intermodality agreement between CT and MRI. METHODS. This retrospective study included 100 patients (mean age, 52.4 ± 11.6 years; 68 men, 32 women) with 104 CRMs (74 malignant) who underwent CT, MRI, and resection between 2010 and 2019. Two radiologists independently evaluated CRMs in separate sessions for each combination of version and modality and assigned a Bosniak class. Diagnostic performance was compared using McNemar tests. Interreader and intermodality agreement were analyzed using weighted kappa coefficients. RESULTS. Across readers and modalities, the proportion of class IIF CRMs was higher for version 2019 than version 2005 (reader 1: 28.8-30.8% vs 6.7-12.5%; reader 2: 26.0-28.8% vs 8.7-19.2%), although 95% CIs overlapped for reader 2 on CT. The proportion of class III CRMs was lower for version 2019 than version 2005 (reader 1: 33.7-35.6% vs 49.0-51.9%; reader 2: 31.7-40.4% vs 37.5-52.9%), although 95% CIs overlapped for all comparisons. Version 2019 showed lower sensitivity for malignancy than version 2005 across readers and modalities (all p < .05); for example, using CT, sensitivity was 75.7% for both readers with version 2019 versus 85.1-87.8% with version 2005. However, version 2019 showed higher specificity than version 2005, which was significant (all p < .05) for reader 1. For example, using CT, specificity was 73.3% (reader 1) and 70.0% (reader 2) with version 2019 versus 50.0% (reader 1) and 56.7% (reader 2) with version 2005. Diagnostic accuracy was not different between versions (version 2005: 76.9-85.6%; version 2019: 74.0-78.8%). Interreader and intermodality agreement were substantial for version 2005 (κ = 0.676-0.782 and 0.711-0.723, respectively) and version 2019 (κ = 0.756-0.804 and 0.704-0.781, respectively). CONCLUSION. Use of version 2019 versus version 2005 of the Bosniak classification system results in a shift in CRM assignment from class III to class IIF. Version 2019 results in lower sensitivity, higher specificity, and similar accuracy versus version 2005. Interreader and intermodality agreement are similar between versions. CLINICAL IMPACT. Version 2019 facilitates recommending imaging surveillance for more CRMs.

Association of Abdominal Aortic Aneurysm and Simple Renal Cysts: A Systematic Review and Meta-Analysis.

BACKGROUND-OBJECTIVE: Prior studies have suggested a higher prevalence of simple renal cysts (SRC) among patients with aortic disease, including abdominal aortic aneurysms (AAA). Thus, the aim of this study was to systematically review all currently available literature and investigate whether patients with AAA are more likely to have SRC. METHODS: This study was performed according to the PRISMA guidelines. A meta-analysis was conducted with the use of random effects modeling and the I-square was used to assess heterogeneity. Odds ratios (OR) and the corresponding 95% confidence intervals (CI) were synthesized to compare the prevalence of several patients' characteristics between AAA vs. no-AAA cases. RESULTS: Eleven retrospective studies, 9 comparative (AAA vs. no-AAA groups) and 3 single-arm (AAA group), were included in this meta-analysis, enrolling patients (AAA: N = 2,297 vs. no-AAA: N = 35,873) who underwent computed tomography angiography as part of screening or preoperative evaluation for reasons other than AAA. The cumulative incidence of SRC among patients with AAA and no-AAA was 55% (95% CI: 49%-61%) and 32% (95% CI: 22%-42%) respectively, with a statistically higher odds of SRC among patients with AAA (OR: 3.02; 95% CI: 2.01-4.56; P< 0.001). The difference in SRC prevalence remained statistically significant in a sensitivity analysis, after excluding the study with the largest sample size (OR: 2.71; 95% CI: 1.91-3.84; P< 0.001). CONCLUSIONS: Our meta-analysis demonstrated a 3-fold increased prevalence of SRC in patients with AAA compared to no-AAA cases, indicating that the pathogenic processes underlying SRC and AAA could share a common pathophysiologic mechanism. Thus, patients with SRC could be considered at high risk for AAA formation, potentially warranting an earlier AAA screening.

Infected simple renal cyst due to Streptococcus pneumoniae rapidly diagnosed by the melting temperature mapping method: a case report.

BACKGROUND: Spontaneous infection of preexisting solitary renal cysts has been documented in adults but is extremely rare in children. To date, no cases of simple renal cysts infected with Streptococcus pneumoniae have been described. Recently, reports have described the diagnosis of bacterial infection using the 16 S rRNA gene as well as the accompanying antimicrobial stewardship for microorganisms that are difficult to culture and for culture-negative cases after preceding antibacterial administration. CASE PRESENTATION: A four-year-old Japanese girl who had a pleuroperitoneal shunt inserted to drain a right pleural effusion due to occlusion of the hepatic portion of the inferior vena cava at three years old visited our hospital due to fever and respiratory discomfort. She was incidentally found to have a right simple renal cyst 10 months before admission. The patient was suspected to have pneumonitis or catheter-related blood stream infection on chest X-ray, which showed right-side pleural effusion. She was diagnosed with invasive pneumococcal infection, as Streptococcus pneumoniae was detected from blood culture on admission. Transient improvements in her symptoms and decreases in the white blood cell count and C-reactive protein level were observed after effective antibiotic administration, but her respiratory condition deteriorated. Enhanced CT showed right renal cyst enlargement and enhancement and thickening of the surrounding wall. Using the melting temperature (Tm) mapping method, S. pneumoniae was rapidly detected directly from pus 4.5 hours after drainage. The specimen culture was negative, but the extracted 16 S rDNA sequence revealed 100 % identity for S. pneumoniae from the same specimen the subsequent day. We successfully performed optimal treatment and reduced medical cost based on the positive Tm mapping method result. CONCLUSIONS: We report the first case of a S. pneumoniae-infected simple renal cyst. The drainage culture was negative, but the Tm mapping method rapidly detected S. pneumoniae directly from the drainage. The Tm mapping method may have great impacts on rapid diagnosis and effective antimicrobial stewardship.