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Oncocytoma. Axial contrast-enhanced CT images demonstrate an enhancing mass (arrow) in the corticomedullary phase (a) and nephrographic phase (b) which cannot be distinguished from renal cell carcinoma.
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Improvements in imaging technology and the expanding use of imaging have led to a rapid increase in the discovery of incidental renal lesions. These can present both the radiologist and the referring clinician with diagnostic dilemmas. This article addresses the most frequently encountered lesions and provides a framework for the diagnostic and man...
Citations
... A related study has shown that renal lesions of less than 1 cm were too small to adequately characterize. (11) To reduce misunderstanding between each RCC and CT imaging, patients who had more than one mass in each kidney, polycystic kidney disease or von Hippel Lindau disease were excluded. The demographic data presenting symptoms and cell type of RCC were collected. ...
Background: Renal cell carcinoma (RCC) is the most common kidney cancer in adults. Computed Tomography (CT) with contrast study is used to diagnose RCC. The enhancement in the nephrogenic phase more than 15 Hounsfield units (HU) is suspected of RCCs. However, this threshold HU shows 15-20% false positive results for RCCs. Objectives: This study aimed to determine RCC enhancement in CT that was below the standard threshold and to analyze the attenuation range of RCCs in noncontrast CT. Methods: Patients with pathological RCC and undergoing CT with contrast study were retrospectively reviewed. An average of attenuation values of three regions of interest (ROI) were measured in noncontrast and nephrogenic phases, by avoiding foci of calcification and peritumoral region. ROI values were calculated for enhancement and range of attenuation values in the noncontrast CT. Results: A total of 152 pathologically RCCs were included in the study. Mean ± SD attenuation values were 32.54 ± 8.02 HU (range 13.3-57.23 HU) and 71.26 ± 33.1 HU (range 16.87-202.8 HU) for noncontrast and contrast CT, respectively. Thirty-one (20.4%) of RCCs did not reach 15 HU enhancement. Using multivariate analysis, significant differences among subtypes (p<0.001) and renal mass less than 7 cm (p<0.001) were observed. In noncontrast CT, using a range of 20-60 HU, 129 (84.9%) RCCs were entirely within this range. To improve the accuracy of RCC diagnosis, the combined use of both non-contrast attenuation group (<20 HU and >20 HU) and enhancement >15 HU could increase the accuracy to 96.7%. Conclusion: One-fifth of RCCs did not reach the standard enhancement threshold that were mostly found in nonclear cell subtype. Especially, when the mass was larger than 7 cm or involved nonclear cell RCCs, the enhancement threshold >15 HU must be carefully used for diagnosis. Using a noncontrast phase regardless HU combined with enhancement >15 HU could improve the accuracy of RCC diagnosis.
... 1 The diagnostic workup for ACC includes the measurement of steroid hormones produced by tumor, imaging via contrast-enhanced CT or magnetic resonance, and biopsy if indicated. 2 An ACC can be quite large, which incurs a higher risk of complications such as vasculature obstruction, related to the size of the malignancy. 3 Thus, it is important to identify these tumors expeditiously and begin treatment as soon as possible. ...
Case presentation:
A 34-year-old woman presented to the emergency department with bilateral lower extremity edema and shortness of breath. She had been seen by her primary care provider. Lab work and a follow-up with endocrinology had been unrevealing. Using point-of-care ultrasound we identified a cystic mass in the right upper quadrant prompting further imaging.
Discussion:
Abdominal and pelvic computed tomography confirmed a mass in the right posterior liver, which was later identified as an adrenocortical carcinoma. Ultrasound is an important diagnostic tool in the setting of lower extremity edema and can be used to assess for heart failure, liver failure, obstructive nephropathy, venous thrombosis, and soft tissue infection. In this case, ultrasound helped expedite the diagnosis and treatment of a rare malignancy.
... Yağ baskılı sekanslarda, yağ uyumlu alanlarda sinyal kaybı yoktu. Tümörlerin ortalama boyutu 6,5 cm (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19) idi. 19 olguda (%90,5) tümörler unilateral iken 2 (% 9,5) olgu da bilateral yerleşim saptandı. ...
Renal anjiomiyolipoma, preoperatif olarak renal hücreli karsinoma ile karışabilen böbreğin benign tümörüdür. Çalışmamızda 2005 – 2011 yılları arasında, renal anjiomiyolipoma tanısı almış olgular, retrospektif olarak incelenerek, klinik ve histopatolojik özellikleri ortaya konuldu. Hasta kayıtlarından elde edilen bilgiler, klinik hikâyeleri, klinik tanısı ve cerrahi materyalin histopatolojik özellikleri not edildi. Olguların 19’ u kadındı. Yaş aralığı 15 - 68 arasındaydı. 13 vakada lezyonlar rastlantısal olarak saptandı. Bilateral lezyonu olan bir vakanın tuberosklerozis olduğu belirlendi. Renal anjiomiyolipomaların karakteristik görüntüleme bulgularını ve renal hücreli karsinoma ile karışabileceğini bilmek önemlidir. Özellikle preoperatif olarak bu tümörleri tanımak nefron koruyucu tedavi seçeneklerini değerlendirmek açısından gereklidir.
... Over the past few decades, there has been a marked increase in the incidence of small renal masses [1]. Increased utilization of cross-sectional imaging has changed the treatment paradigm for many renal masses. ...
Treatment options for small renal masses include partial nephrectomy (PN), ablation and active surveillance. We sought to compare patients who met the criteria for percutaneous ablation but underwent robotic PN to the rest of our robotic PN cohort. This was done in order to detect any safety concerns and to define any risk factors that might contraindicate the use of robotic PN, an oncologically superior procedure, in patients who qualify for ablation.
Our departmental renal mass registry was queried for patients who underwent robotic PN but also met criteria for percutaneous ablation. These were compared to the rest of the robotic PN cohort. Demographics, perioperative characteristics and recurrence data were compared.
Overall, 321 robotic PNs were identified. Of these, 26 (8.1%) met ablation criteria. Among patient characteristics, age and BMI were similar in both groups. Among operative characteristics, estimated blood loss (EBL) and operative time were similar. Warm ischemia time was significantly less for patients who met ablation criteria (14 vs. 17 minutes, p = 0.002). Mean tumor size was smaller for patients who met ablation criteria (2.3 vs. 2.7 cm, p = 0.012). Among postoperative characteristics, complications were similar overall and when present, stratified by Clavien grade.
Robotic PN is a safe, effective treatment option for small renal masses, even in patients who meet ablation criteria. There were no recurrences in our cohort and the majority of complications were Clavien grade 1.
... In the case of an incidentally detected renal lesion in a cancer patient, the incidental abnormality may represent metastatic disease, a second primary malignancy or a benign lesion. The diagnosis and management of such incidental findings will depend in part on the clinical setting, the pathology and stage of underlying primary malignancy and the imaging features of the incidental abnormality [3][4][5][6]. ...
The increasing use of cross-sectional imaging has led to greater detection of incidental lesions in oncology and non-oncology patients. These incidental lesions are unexpected and usually asymptomatic abnormalities that are identified when imaging for other purposes. These incidental lesions create a diagnostic and management challenge for radiologists and clinicians [1]. They may result in patients having unnecessary investigations and treatment, which is not without risks or expense. The American College of Radiologists has developed guidelines and recommendations for incidentally detected lesions on abdominal imaging [2]. The guidance developed addresses incidental findings in the kidney, liver, adrenal glands and pancreas but does not deal specifically with cancer patients.
In the case of an incidentally detected renal lesion in a cancer patient, the incidental abnormality may represent metastatic disease, a second primary malignancy or a benign lesion. The diagnosis and management of such incidental findings will depend in part on the clinical setting, the pathology and stage of underlying primary malignancy and the imaging features of the incidental abnormality [3-6].
In terms of imaging characterisation many incidental kidney lesions can be fully characterised using ultrasound, CT or MRI. In characterising a renal mass, in general it is important to first ensure that the mass is not the result of non-neoplastic conditions that may mimic a tumour. For example focal bacterial pyelonephritis, pseudotumours such as columns of Bertin, hypertrophied tissue adjacent to scars, vascular anomalies, aneurysms and infarcts.
Further imaging characterisation may suggest that the lesion is a benign cystic renal tumour, i.e. Bosniak I or II lesions. If the lesion is solid, unless there are features in keeping with an angiomyolipoma (AML), it is usually not possible to differentiate benign from malignant primary tumour or metastases to the kidney. Therefore either cystic lesions or solid lesions in which malignancy cannot be excluded may need further assessment and this is an indication for a renal biopsy.
Metastases to the kidney are very uncommon. Renal metastases frequently do not present clinical symptoms and many patients have no haematuria. Traditionally, metastases to the kidney are thought to be multiple and bilateral, however descriptions are limited to case reports. The most common malignancies metastasing to the kidney are lung and breast cancer. Previous imaging or history is also useful in evaluating metastases to the kidney as there is often widespread metastatic disease with renal involvement. Isolated metastasis is very rare and may need a biopsy in order to distinguish it from primary renal neoplasm.
... Almost all renal masses containing macroscopic fat are AMLs. 2 Fat-containing renal cell carcinomas (RCCs) are so rare, they are only described in case reports. Moreover, all of these lesions contained calcifications, 3-7 a finding extremely rare in AMLs. 2 ...
... Moreover, all of these lesions contained calcifications, 3-7 a finding extremely rare in AMLs. 2 ...
... Newer imaging techniques, particularly in magnetic resonance imaging, may provide better capability to diagnosis fat-poor AMLs in the future. 2 The 2 mainstays of treatment for AML are surgery and renal angioembolization (RAE). Other management strategies include surveillance, total nephrectomy and investigational medical management, such as hormonal therapy or use of mammalian target of rapamycin (mTOR) inhibitiors, such as sirolimus. ...
Background: Angiomyolipoma (AML) is a benign renal neoplasm.First-line therapy includes renal preserving surgery or angioembolization(RAE), both with good outcomes in isolated studies.However, there are no comparative randomized trials and no clinicalguidelines to help clinicians decide between these treatmentmodalities. Our study examines the patterns of AML treatment ata tertiary care centre to evaluate how local urologists have beentreating this disease.Methods: This is a retrospective study of all AMLs treated at theVancouver General Hospital (Vancouver, BC, Canada) over thepast 10 years with either RAE or surgical excision. Searches wereperformed of the radiology and pathology dictation systems, usingthe following keywords: AML, angiomyolipoma, angioembolization,embolization, surgery, partial nephrectomy and nephrectomy.Results: At our institution, more AMLs were treated by surgerythan angioembolization (42 vs. 17 cases). Angioembolization wasmore often chosen for cases of multifocal AML (35% vs. 7%) andacute hemorrhage (50% vs. 14%). In the angioembolization cases,particles were the embolic agent of choice (used 40% of the time).Conclusions: Angioembolization allows rapid patient stabilizationin cases of acute hemorrhage, and provides good renal preservationin cases of multifocal AML. It may also be preferred in largemasses when partial nephrectomy is not feasible. Surgery should beperformed in cases of diagnostic uncertainty or complex vascularanatomy not amenable to RAE. Prospective randomized studies areneeded to compare RAE and surgery to better define their indicationsin sporadic AML.Contexte : Un angiomyolipome (AML) est une tumeur bénigne durein. Le traitement de première intention comprend une chirurgiede conservation rénale ou une angioembolisation rénale, quiont toutes deux donné de bons résultats dans des études isolées.Cependant, aucun essai comparatif randomisé n’a été mené et iln’existe pas de lignes directrices pour aider les cliniciens à choisirentre ces modalités thérapeutiques. Notre étude a examiné les tendancesdans le traitement de l’AML à un centre de soins tertiairespour évaluer comment les urologues y traitent cette maladie.Méthodologie : Il s’agit d’une étude rétrospective de tous les AMLtraités au Vancouver General Hospital (Vancouver, C.-B., Canada)au cours des 10 dernières années, soit par chirurgie de conservationrénale ou par angioembolisation. Des recherches ont été effectuéesdans les systèmes de dictée vocale de radiologie et de pathologieen utilisant les mots-clés anglais suivants : AML, angiomyolipoma,angioembolization, embolization, surgery, partial nephrectomy etnephrectomy.Résultats : Dans notre établissement, plus de cas d’AML ont ététraités par chirurgie que par angioembolisation (42 cas contre 17).L’angioembolisation a été plus souvent choisie dans les cas d’AMLmultifocal (35 % contre 7 %) et d’hémorragie aiguë (50 % contre14 %). Dans les cas traités par angioembolisation, les particulesont été l’agent embolique privilégié (utilisées dans 40 % des cas).Conclusions : L’angioembolisation permet de stabiliser rapidementl’état du patient en cas d’hémorragie aiguë, et offre une bonneconservation rénale en cas d’AML multifocale. Elle peut aussi êtrepréférable en présence de larges masses quand la néphrectomiepartielle n’est pas possible. La chirurgie doit être réalisée en casd’incertitude diagnostique ou d’anatomie vasculaire complexe nese prêtant pas à l’angioembolisation rénale. Des études prospectivesrandomisées sont nécessaires pour comparer l’angioembolisationrénale et la chirurgie afin de mieux définir leurs indications dansles formes sporadiques d’AML.
... IN the last 30 years there has been a well documented shift in the diagnosis of renal masses. 1 The increased use of cross-sectional abdominal imaging during this period has altered the diagnostic process such that the majority of renal masses are now being discovered incidentally while they are small and asymptomatic. 2 This shift, along with the emergence of new technologies, has changed the treatment paradigm toward nephron sparing and minimally invasive methods. ...
With the increased incidence of low stage renal cancers, thermal ablation technology has emerged as a viable treatment option. Current AUA (American Urological Association) guidelines include thermal ablation as a treatment modality for select individuals. We compared the laparoscopic and percutaneous approach for the radio frequency ablation of renal tumors under the guidance of urological surgeons.
We reviewed our radio frequency ablation database of patients with renal masses undergoing laparoscopic or computerized tomography guided percutaneous radio frequency ablation with simultaneous peripheral fiberoptic thermometry from November 2001 to January 2011 at a single tertiary care center. Data were collected on patient demographics, and surgical and clinicopathological outcomes stratified by approach.
A total of 298 patients with 316 renal tumors underwent laparoscopic (122 tumors) or computerized tomography guided (194 tumors) radio frequency ablation. There were no statistically significant differences between the laparoscopic and computerized tomography guided radio frequency ablation groups with respect to patient demographics, complication rates and renal functional outcomes (p>0.05). The 3-year Kaplan-Meier estimation of radiographic recurrence-free probability was 95% for computerized tomography guided radio frequency ablation and 94% for laparoscopic radio frequency ablation (p=0.84). Subanalysis of the 212 (67%) renal cell carcinoma tumors showed a 3-year Kaplan-Meier estimation of oncologic recurrence-free probability (post-ablation biopsy proven viable tumor) of 94% for computerized tomography guided radio frequency ablation and 100% for laparoscopic radio frequency ablation (p=0.16). Median followup was 21 months for laparoscopic radio frequency ablation) and 19 months for computerized tomography guided radio frequency ablation.
Laparoscopic and computerized tomography guided radio frequency ablation appear safe and effective with statistically equivalent rates of complications and recurrence.
... In our cohort, asymptomatic focal renal parenchymal masses measuring at least 1 cm in diameter were identified in 14.4% of subjects. Subcentimeter masses were not considered in our analysis because incidental masses smaller than 1 cm can generally be ignored [10,17]. The prevalence in our study was similar to that in previous reports, particularly when subcentimeter masses were excluded [6,18]. ...
... Finally, we CT of Renal Masses did not include masses smaller than 1 cm. Although it is conceivable that these very small masses could be malignant, they are almost always benign, particularly when they appear cystic, and are difficult to characterize completely with imaging [10,17]. If we had included them in our analysis, we might have skewed the results. ...
The purposes of this study were to investigate the frequency and clinical relevance of the incidental finding of renal masses at low-dose unenhanced CT and to analyze the results for features that can be used to guide evaluation.
Images from unenhanced CT colonographic examinations of 3001 consecutively registered adults without symptoms (1667 women, 1334 men; mean age, 57 years) were retrospectively reviewed for the presence of cystic and solid renal masses 1 cm in diameter or larger. An index mass, that is, the most complex or concerning, in each patient was assessed for size, mean attenuation, and morphologic features. Masses containing fat or with attenuation less than 20 HU or greater than 70 HU were considered benign if they did not contain thickened walls or septations, three or more septations, mural nodules, or thick calcifications. Masses with attenuation between 20 and 70 HU or any of these features were considered indeterminate. The performance of CT colonography in the detection of renal cell carcinoma was calculated for masses with 2 or more years of follow-up.
At least one renal mass was identified in 433 (14.4%) patients. The mean size of the index masses was 25 ± 16 mm; 376 (86.8%) masses were classified as benign and 57 (13.2%) as indeterminate. The 20- to 70-HU attenuation criterion alone was used for classification of 53 indeterminate lesions. Follow-up data (mean follow-up period, 4.4 years; range, 2-6.3 years) were available for 353 (81.5%) patients with masses (41 indeterminate, 312 benign). Four of the 41 indeterminate masses were diagnosed as renal cell carcinoma. The sensitivity and specificity for renal cell carcinoma on the basis of the indeterminate criteria were 100% and 89.4%. The positive and negative predictive values were 9.8% and 100%.
The incidental finding of a renal mass is relatively common at unenhanced CT, but imaging criteria can be used for reliable identification of most of these lesions as benign without further workup. Mean attenuation alone appears reliable for determining which renal masses need further evaluation.
Resumen
Los angiomiolipomas (AML) renales, responsables del 1-3% de todos los tumores renales, son neoplasias benignas de origen mesenquimal compuestas por cantidades variables de tejido adiposo maduro, músculo liso y vasos sanguíneos dismórficos, que hacen parte del grupo de neoplasias de células epitelioides perivasculares (PEComas). Por lo general son asintomáticos, pero el incremento en el uso del ultrasonido, la tomografía computarizada y la resonancia magnética ha aumentado el diagnóstico y, por consiguiente, la incidencia de estas lesiones. Aunque las lesiones con contenido graso de origen renal corresponden en su gran mayoría a AML, es importante hacer diagnóstico diferencial con carcinoma de células renales y liposarcoma retroperitoneal, por lo que es de gran importancia reconocer las características en imágenes típicas y las posibles variantes. Las nuevas modalidades en biología molecular han permitido describir variantes histológicas como el AML epitelioide, que requiere un manejo distinto por su potencial de malignización. Los avances en el tratamiento endovascular han permitido establecer los criterios de riesgo para hemorragia y otras complicaciones.
