Nephrometry scoring systems: their importance for the planning of nephron-sparing surgery and the relationships among them / Escores nefrométricos: sua importância para o planejamento da nefrectomia parcial e as relações entre eles

Abstract In recent years, the development of new imaging techniques and scoring systems have improved the diagnosis and management of small renal masses. Imaging-based nephrometry scoring systems play an interesting role in the planning of nephron-sparing surgery, providing surgeons with the information necessary to determine the complexity of the renal mass, to deliver the appropriate postoperative care, and to predict adverse outcomes. The aim of this study was to review nephrometry scoring systems, evaluating their characteristics and the relationships among them. The urology and radiology communities should decide which nephrometry scoring system will prevail and be used in daily practice.

Resumo O diagnóstico e o manejo das pequenas massas renais têm sido aprimorados nos últimos anos com o desenvolvimento de técnicas de imagem e escores que desempenham papel interessante no planejamento da nefrectomia parcial, fornecendo informações importantes ao cirurgião para determinar o tipo de tratamento em relação a complexidade da massa renal, cuidados pós-operatórios e previsão de complicações após as cirurgias. O objetivo deste estudo é revisar os escores de nefrometria, suas características e relações entre eles no cenário da cirurgia. Os serviços de urologia e radiologia devem decidir qual é o melhor escore de nefrometria para ser utilizado na prática diária.

INITIAL EXPERIENCE WITH ENDOSCOPIC ULTRASOUND-GUIDED FINE NEEDLE ASPIRATION OF RENAL MASSES: indications, applications and limitations / Ecoendoscopia com punção aspirativa de massas renais: indicações, aplicações e limitações

Context Tissue sampling of renal masses is traditionally performed via the percutaneous approach or laparoscopicaly. The utility of endoscopic ultrasound to biopsy renal lesions it remains unclear and few cases have been reported. Objectives To evaluate the feasibility and outcome of endoscopic ultrasound fine needle aspiration of renal tumors. Methods Consecutive subjects undergoing attempted endoscopic ultrasound fine needle aspiration of a kidney mass after evaluation with computerized tomography or magnetic resonance. Results Ten procedures were performed in nine male patients (median age 54.7 years) on the right (n = 4) and left kidney (n = 4) and bilaterally (n = 1). Kidney masses (median diameter 55 mm ; range 13-160 mm) were located in the upper pole (n = 3), the lower pole (n = 2) and the mesorenal region (n = 3). In two cases, the mass involved more than one kidney region. Surgical resection confirmed renal cell carcinoma in six patients in whom pre-operative endoscopic ultrasound fine needle aspiration demonstrated renal cell carcinoma. No complications were reported. Conclusions Endoscopic ultrasound fine needle aspiration appears as a safe and feasible procedure with good results and minimal morbidity. .

Contexto A amostragem de tecido de massas renais é tradicionalmente realizada através da abordagem percutânea ou pelo método laparoscópico. A utilidade do ultrassom endoscópico para biópsia de lesões renais ainda não está clara e poucos casos foram relatados na literatura. Objetivos Avaliar a factibilidade e os resultados da biópsia de tumores renais guiada por ultrassom endoscópico. Métodos Trata-se de uma série retrospectiva de casos de biópsias ecoguiadas de massa renal após avaliação com tomografia computadorizada ou ressonância magnética. Resultados Dez procedimentos foram realizados em nove pacientes do sexo masculino (idade média de 54,7 anos), no rim direito (n = 4), esquerdo (n = 4) e bilateralmente (n = 1). Massas renais (diâmetro médio 55 mm; variando de 13 a 160 mm) localizadas no pólo superior (n = 3), inferior (n = 2) e na região mesorenal (n = 3). Em dois casos, a massa envolvida mais de uma região renal. A ressecção cirúrgica confirmou carcinoma de células renais em seis pacientes nos quais a biópsia ecoguiada pré-operatória demonstrava carcinoma de células renais. Não foram relatadas complicações. Conclusões A biópsia de massas renais guiadas por ultrassom endoscópico é um procedimento seguro e viável, com bons resultados e mínima morbidade. .

Radiologic Differentiation Between Homogeneously Solid Renal Cell Carcinoma and Muscle-Predominant Renal Angiomyolipoma

PURPOSE: To compare the differential radiologic findings of renal cell carcinoma presenting as a homogeneous solid mass (HS-RCC) and muscle-predominant angiomyolipoma (MP-AML). MATERIALS AND METHODS: Nine of 76 surgically and pathologically proven RCCs presenting at CT or magnetic resonance (MR) imaging as a homogeneous solid mass, and four cases of MP-AML were included in this study. Echogenicity at sonography, attenuation at non-enhanced CT (NECT), the contour of the mass, signal intensities at T1- and T2-weighted MR imaging, the existence of a capsule, and the pattern and degree of enhancement at CT and MR imaging were retrospectively analyzed. RESULTS: Two of five HS-RCCs were isoechoic and three were hyperechoic. Two of three MP-AMLs, however, were isoechoic, and one was mixed echoic. All nine HS-RCCs were round or oval in shape, but three MPAMLs were lobulated and one was round. At NECT, seven of eight HS-RCCs were isodense and one was hypodense compared to surrounding normal renal parenchyme, but three MP-AMLs were hyperdense masses and one was isodense. At enhanced CT, HS-RCCs showed various degrees of homogeneous enhancement, but all MP-AMLs showed moderate homogeneous enhancement. All three MP-AMLs demonstrated heterogeneous hypointensity at T2-weighted MRI and homogeneous hypointensity at T1-weighted MRI. HS-RCCs showed various signal intensities at both T1- and T2-weighted MRI, and in five cases, heterogeneous high signal intensity at T2-weighted MRI. Capsules were observed in seven of nine HS-RCCs but not in any of the three MP-AMLs. At enhanced T1-weighted MRI, MP-AMLs showed mild to moderate enhancement, but HSRCCs showed mild, moderate, and strong enhancement in two, two, and five cases, respectively. CONCLUSION: Echogenicity, density at NECT, signal intensity at MR T2-WI, the contour of the mass, and the existence of a capsule are features which are useful in the differential diagnosis of HS-RCC and MP-AML.

Spiral CT Findings of Chromophobe Renal Cell Carcinoma: Correlation with Pathologic Features and Prognosis

PURPOSE: To describe the spiral CT findings of CRCC and to correlate these with the pathologic features, nuclear grading, tumor staging, and prognosis. MATERIALS AND METHODS: We encountered eleven cases of CRCC among 167 cases of histopathologically proven RCC, retrospectively evaluating the spiral CT findings of CRCC including tumor size, internal texture, attenuation, margin, and the involvement of veins or lymph nodes. In addition, the CT findings were correlated with the pathologic features, Fuhrman's nuclear grade, Robson's staging, and the prognosis. Between 27 and 80 (mean, 49.6) months later, the follow-up CT scans of tea patients were examined for tumor recurrence. RESULTS: All tumors, which ranged in size from 2.5 to 15 (mean, 7.7) cm, were solid and well demarcated from renal parenchyma. Pre-contrast CT scans showed that their attenuation was equal to (n=1) or slightly lower (n=10) than that of renal parenchyma, and on early and delayed phase post-contrast enhanced scans, attenuation was low in all cases. In three, focal areas in which attenuation was lower than in the rest of the tumor were observed; histopathologically, these represented hyalinization. There was neither venous nor lymph node involvement, and no distant metastasis. Histopathologic examination demonstrated cystic change (n=1), hemorrhage or necrosis (n=5), complete encapsulation (n=3) and perirenal fat infiltration (n=3). Nuclear grading was II (n=6) or III (n=5), and tumor staging was I (n=8) or II (n=3). Among the five cases in which the nuclear grade was III, three were stage I and two were stage II. Follow-up scans showed no evidence of tumor recurrence, and all patients survived. CONCLUSION: Pre-, early- and late-phase post-contrast enhonced spiral CT scans showed that the attenuation of a CRCC was lower than that of renal parenchyma. Even where the nuclear grade was higher, a well-demarcated soild mass was observed, the tumor stage was lower and the prognosis better.

CT Staging of Renal Pelvis Tumor

PURPOSE: To assess the value of computed tomography (CT) in the preoperative staging of transitional cellcarcinoma (TCC) of the renal pelvis. MATERIALS AND METHODS: We retrospectively evaluated the CT TNM staging of 38patients with TCC of the renal pelvis who had undergone preoperative abdominal CT examination between January 1990and January 1998. In CT staging for differentiation between early-stage (TO-2) and advanced-stage disease (T3-T4),three criteria were used, namely the presence or obliteration of the renal sinus fat layer, the smoothness orirregularity of margin between the tumor and renal parenchyma, and the presence or absence of hydronephrosisproximal to the tumor. CT staging was performed by two genitourinary radiologists blinded to the pathologicresults, and was compared with pathologic staging. RESULTS: Pathologic results revealed 19 cases of early stagedisease (TO=8, T1=9, T2=2) and 19 of advanced stage (T3=12, T4=7). Overall CT staging accuracy was 82%(31/38);fourcases were overstaged and three were understaged. In early-stage disease, sensitivity and specificity were 79%,and 84%, and in advanced stage disease were 83% and 80%. Three of four overstaged cases showed hydronephrosisproximal to the tumor. In the second CT staging, using proximal hydronephrosis of the tumor as a criterion forearly-stage disease, the sensitivity and specificity of early-stage disease were 95% and 75%, respectively, andthe specificity of advanced-stage disease was 95%. CONCLUSION: When hydronephrosis proximal to a tumor wasconsidered to be a sign of early stage disease, the CT staging of renal pelvic TCC was highly accurate.

Mucinous Cystadenoma of Renal Collecting Duct Origin: A Case Report

We report a case of mucinous epithelial tumor (mucinous cystadenoma) in the renal pelvis. This type of tumor shows a non-specific cystic mass, and sometimes has wall calcification, it very rarely originates in multi-potential renal pelvic epithelium. We report the imaging findings of the tumor and review the previous literature.

CT Findings of Renal Parenchymal Infiltration in Pelvocalyceal Transitional Cell Carcinoma

PURPOSE: The purpose of this study was to evaluate the CT findings of renal parenchyma infiltrated by pelvocalyceal transitional cell carcinoma. MATERIALS AND METHODS: This study included 28 patients in whom transitional cell carcinoma was dignosed after nephrectomy. CT findings were analyzed for the presence or absence of renal parenchymal infiltration; diagnostic criteria for this included parenchymal inhomogeneous low attenuation, ill-defined margin between the mass and renal parenchyma, or focal calyceal dilatation. To detect renal parenchymal infiltration by transitional cell carcinoma, we evaluated the frequency, sensitivity and specificity of each CT finding. RESULTS: Pathologic reports showed that renal parenchymal infiltration had occurred in 17 of 28 patients, (60.7%) ; on CT scans, renal parenchymal infiltration was seen in 15 of these 28 (53.6%). It two patients who did not show CT findings of renal parenchymal infiltration, pathologic examination revealed parenchymal invasion. All 15 patients who showed renal infiltration on CT had parenchymal inhomogeneous low attenuation (sensitivity: 88.2%, specificity : 100%), 13 showed ill-defined margin of the mass (sensitivity : 76.5%, specificity : 100%), and six showed focal dilatation of the calyx (sensitivity : 35.3%, specificity : 100%). CONCLUSION: In patients with pelvocalyceal transitional cell carcinoma, CT findings of parenchymal inhomogeneous low attenuation, ill-defined margin of mass, and focal calyceal dilatation suggest renal parenchymal infiltration, and these findings may be helpful in preoperative prognosis.

Multiphasic spiral CT of renal masses: Comparison among phases following contrast injection

PURPOSE: To assess the utility of multiphasic spiral CT for characterizing renal masses. MATERIALS AND METHODS: The study included 36 patients (53 lesions) referred for the evaluation of renal masses suspected on the basis of the results of sonography or radiography. Spiral CT of the kidneys was performed prior to and following power injection of intravenous contrast material (Optiray-320). Postcontrast imaging data were obtained and analyzed during early and late corticomedullary (20-30-second delay), nephrographic (60-70-second delay), and excretory (5-minute delay) phases. During each phase, the ability to detect renal masses was evaluated, and the ability to diagnose these masses on routine and multiphasic CT was assessed. Routine precontrast and excretory phase CT studies were performed and the usefulness of each phase for the diagnosis of renal cell carcinoma (RCC) and transitional cell carcinoma (TCC) was evaluated. RESULTS: The rates for the detection of renal masses were as follows: 94.3% on precontrast scan, 93.8% during the early corticomedulolary phase (ECMP), 98.1% during the late corticomedullary phase (LCMP), 100% during the nephrographic phase (NP), and 98.1% during the excretory phase (EP). During both routine and multiphasic CT, diagnostic accuracy was 96.2%, though for differential diagnosis, multiphasic CT was more helpful than routine CT in 4/16 cases of RCC and 2/8 cases of TCC. The highest for lesion characterization, during the LCMP in RCC, and the LCMP and NP in TCC ; for evaluation of tumor margin during the EP in both RCC and TCC ; for delineation of the renal artery, during the LCMP in both RCC and TCC ; for delineating the renal vein, during the NP in RCC, and the LCMP in TCC. CONCLUSION: For the detection and correct diagnosis oflesions, multiphasic CT was not superior to routine CT, but for the characterization of RCC and TCC, the former was helpful. The most useful phase can differ according to the kind of renal mass, and so for characterization of the mass, the most appropriate phase must be selected.

Imaging Diagnosis in Various Renal Sinus Lesion

The renal sinus extends from the perinephric space into the deep recess situated on the medial border of the kidney. Contained within the space are the pelvocalyceal system, fat and lymph nodes. Arteries, veins, lymphatic channels and nerves of the autonomic nervous system traverse the sinus, and various pathological conditions may occur in this area. These various sinusal lesions may present a similar imaging appearance, and diagnostic errors may frequently occur, especially if diagnosis is attempted without first clearly understanding the several possibilities. This pictorial essay demonstrates various renal sinus lesions and emphasizes the proper combination of multimodal imaging. For evaluation of the extent of the lesious, CT is the preferred imaging modality, since this best depicts the anatomy of the renal sinus. Using a proper combination of multimodal imaging, specific diagnosis was in most cases possible.

Acquired Cystic Kindey Disease in Dialysis and Renal Transplant Patients: Ultrasonography and CT Analysis

PURPOSE: To evaluate by US and CT the incidence and complications of acquired cystic kidney disease (ACKD) in dialysis and renal transplant patients and to compare the effectiveness of US and CT in the diagnosis of this entity. MATERIALS AND METHODS: This study was prospectively performed in 70 dialysis patients and 13 renal transplant patients, and excluded any with multiple renal cysts or polycystic kidney disease, on as seen on initial films. US were obtained in all patients, and CT scans were randomly obtained in 27 who had been on dialysis for 3 years or more; all these US and CT scans were analyzed, with particular emphasis on whether or not cysts were present. In order to correlate the numbers of cysts with duration of dialysis, all patients were assigned to one of three groups, according to the number of cysts found (group 1, 0; group 2, 1-4; group 3, >4).Only group 3 was diagnosed as suffering from ACKD. In order to compare the cyst-detection capability of US with that of CT, 27 dialysis patients who had undergone US and CT were divided into four groups according to the numberof cysts found (grade 1, 0; grade 2, 1-4; grade 3, 5-10; grade 4, >10). RESULTS: Seventy dialysis patients were divided according to the results of US, as follows : group 1, 20%; group 2, 47.1%; group 3, 32.9%. The mean duration of dialysis in group 1 (31.9 months) was statistically different from that in group 2 (50.6 months) and in group 3 (95.8 months) (p<0.000). Thirteen renal transplant patients were divided as follows : group1, 61.5%; group 2, 38.5%; group 3, 0%. In dialysis patients with ACKD, complications noted were renal cell carcinoma(n=1), hemorrhagic cysts(n=2), and hematomas(n=2) Among the 27 dialysis patients who underwent CT, this and US showed an equal grade of cystic change in 53.7%, while CT showed a higher grade in 46.3%. The detection rate of ACKD in these 27 patients was 46% on US and 63% on CT. CONCLUSION: A prolongation of dialysis corresponded to an increased incidence of ACKD; renal neoplasm and hemorrhage may occur in dialysis patients, but ACKD and its complications did not develop in renal transplant patients. In long-term dyalysis patients, regular follow-up studies of kidneys using US or CT are therefore needed. CT was superior to US in diagnosing ACKD.