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Kobayashi M, Yokoyama M, Yuki H, Kamai T. Natural History and Management of Ultrasound-detected Small Renal Angiomyolipoma. J Med Ultrasound 2024; 32:154-160. [PMID: 38882610 PMCID: PMC11175373 DOI: 10.4103/jmu.jmu_73_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 07/08/2023] [Accepted: 07/18/2023] [Indexed: 06/18/2024] Open
Abstract
Background Recent advances in imaging methods increased the incidental detection of small renal angiomyolipoma (AML). However, guidelines for managing small AML are lacking, and decisions about imaging frequency and timing of intervention are made on an individual basis. This study aims to investigate the clinical behavior of small sporadic AML and propose an optimal follow-up strategy. Methods The study is a retrospective analysis of 168 individuals who had hyperechoic lesions, suggestive of AML detected during abdominal ultrasound as a part of their health checkup. The clinical information of the individuals, including tumor characteristics and renal function, was reviewed. Statistical analysis was performed to identify factors associated with tumor growth and renal function. Results Most AMLs were small (≤20 mm) and did not exhibit malignant characteristics. The tumors showed a slow growth rate, with a mean growth rate of 0.24 mm/year. Only a small proportion of cases (1.2%) required intervention due to significant enlargement. Factors such as tumor size and gender were not significantly associated with tumor growth rate or renal function. However, younger patients showed a higher tumor growth rate and a more pronounced decline in renal function. Conclusion Small sporadic AMLs have a slow growth rate and little risk of malignancy. Neither tumor size nor gender was predictive factors for tumor growth or renal function. Nevertheless, close monitoring of tumor growth and renal function is advised, particularly in younger patients. This study highlights the need for further research and guidelines to establish an optimal surveillance protocol for small AMLs.
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Affiliation(s)
- Minoru Kobayashi
- Department of Urology, Utsunomiya Memorial Hospital, Utsunomiya, Tochigi, Japan
| | - Megumi Yokoyama
- Department of Urology, Dokkyo Medical University Nikko Medical Center, Nikko, Tochigi, Japan
| | - Hideo Yuki
- Department of Urology, Dokkyo Medical University Nikko Medical Center, Nikko, Tochigi, Japan
| | - Takao Kamai
- Department of Urology, Dokkyo Medical University, Mibu, Japan
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Chen AF, McGahan JP, Wilson MD, Larson MC, Vij A, Kwong A. Are There Ultrasound Features to Distinguish Small (<3 cm) Peripheral Renal Angiomyolipomas From Renal Cell Carcinomas? JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2023; 42:2083-2094. [PMID: 36988571 DOI: 10.1002/jum.16229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 02/22/2023] [Accepted: 03/19/2023] [Indexed: 06/19/2023]
Abstract
BACKGROUND Small echogenic renal masses are usually angiomyolipomas (AMLs), but some renal cell carcinomas (RCCs) can be echogenic and confused with an AML. OBJECTIVES This is a study to evaluate any distinguishing demographic and sonographic features of small (<3 cm) peripheral AMLs versus peripheral RCCs. METHODS This is a HIPAA-compliant retrospective review of the demographics and ultrasound features of peripheral renal AMLs compared with a group of peripheral RCCs. All AMLs had confirmation of macroscopic fat as noted on thin-cut CT or fat-saturation MRI sequence images. All RCCs were pathologically proven. Statistical analysis was used to compare findings in the two groups. RESULTS There were a total of 52 patients with 56 AMLs, compared with 42 patients with 42 RCCs. There were 42 females in the AML group versus 10 females in the RCC group (P < .0001). The AML diameters (15.7 mm × 12.0 mm) were statistically significantly smaller (Plargest = .0085, Psmallest < .001) than the diameters of the RCCs (19.9 mm × 18.5 mm). Ultrasound features found to be statistically different between the two groups were the ratio of the largest dimension to the smallest dimension (P < .001), a lobulated versus smooth margin of the AML (26 vs 30) compared with the RCC group (3 vs 39) (P = .0012), and an "unusual" versus a round shape (P < .001) of the AML group (45 vs 11) compared with the RCC group (9 vs 33). In the multivariable model, the patient sex, margin, and mass shape were predictive of AML, with an area under the receiver operating characteristic curve of 0.92. CONCLUSION For a small (<3 cm) peripheral echogenic mass in a female patient, a lobulated lesion with an unusual shape is highly predictive of being an AML.
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Affiliation(s)
- Anthony F Chen
- Department of Radiology, University of California, Davis School of Medicine, Sacramento, California, USA
| | - John P McGahan
- Department of Radiology, University of California, Davis School of Medicine, Sacramento, California, USA
| | - Machelle D Wilson
- Department of Public Health Sciences, Division of Biostatistics, UC Davis, Sacramento, California, USA
| | - Michael C Larson
- Department of Radiology, University of California, Davis School of Medicine, Sacramento, California, USA
| | - Arjun Vij
- Department of Radiology, University of California, Davis School of Medicine, Sacramento, California, USA
| | - Austin Kwong
- Department of Radiology, University of California, Davis School of Medicine, Sacramento, California, USA
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Krishna S, Bhayana R. Subcentimeter Echogenic Renal Lesions: Point-They Can Be Safely Ignored When Uniformly Echogenic. AJR Am J Roentgenol 2023; 221:309-310. [PMID: 36946898 DOI: 10.2214/ajr.23.29316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2023]
Affiliation(s)
- Satheesh Krishna
- University Medical Imaging Toronto, Joint Department of Medical Imaging, University Health Network, Mount Sinai Hospital and Women's College Hospital, University of Toronto, Toronto General Hospital, 200 Elizabeth St, Toronto, ON M5G 2C4, Canada
| | - Rajesh Bhayana
- University Medical Imaging Toronto, Joint Department of Medical Imaging, University Health Network, Mount Sinai Hospital and Women's College Hospital, University of Toronto, Toronto General Hospital, 200 Elizabeth St, Toronto, ON M5G 2C4, Canada
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Kwong A, Mitchell A, Wang D, McGahan JP. Etiology of Small Echogenic Renal Masses. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2022; 41:2567-2575. [PMID: 35043978 DOI: 10.1002/jum.15946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 12/09/2021] [Accepted: 01/02/2022] [Indexed: 06/14/2023]
Abstract
OBJECTIVES There has been controversy on how frequently small echogenic masses are angiomyolipomas (AMLs) versus renal cell carcinoma (RCC) and how best to manage these echogenic masses. We performed this study to determine the etiologies of echogenic renal masses and compare them with prior publications to reach possible management decisions. METHODS This is a retrospective chart review of all consecutive renal ultrasound examinations performed at our institution between January 2015 and December 2016, with an ultrasound report finding containing the wording "echogenic" and "mass." This yielded 6462 total examinations. A total of 107 echogenic lesions met inclusion and exclusion criteria with correlative computed tomography, pathology, or long-term (>5 years) follow-up ultrasound. These lesions were stratified into those that were ≤2 cm and those that were >2 cm. RESULTS Almost all masses were benign, with the majority (79/107) being AMLs (73.8%); 64 of the 79 (81%) of the AMLs were in female patients. Two of the 107 masses were RCCs, and 1 mass was an oncocytic neoplasm. There were 77 of the masses that were ≤2 cm and these masses were benign except for one lesion of an oncocytic neoplasm. There were 30 of the 107 masses >2 cm, with 2 of the 30 (6.7%) being RCCs. CONCLUSIONS Incidental echogenic renal masses are most commonly AMLs. However, some masses may be RCCs. In comparing our results with the prior literature, we feel that small echogenic renal masses ≤1 cm usually require no further evaluation, while masses greater than that size require other imaging.
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Affiliation(s)
- Austin Kwong
- Department of Radiology, UC Davis Health SOM, Sacramento, California, USA
| | - Ana Mitchell
- Department of Radiology, UC Davis Health SOM, Sacramento, California, USA
| | - Danielle Wang
- Department of Radiology, UC Davis Health SOM, Sacramento, California, USA
| | - John P McGahan
- Department of Radiology, UC Davis Health SOM, Sacramento, California, USA
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Habibollahi P, Sultan LR, Bialo D, Nazif A, Faizi NA, Sehgal CM, Chauhan A. Hyperechoic Renal Masses: Differentiation of Angiomyolipomas from Renal Cell Carcinomas using Tumor Size and Ultrasound Radiomics. ULTRASOUND IN MEDICINE & BIOLOGY 2022; 48:887-894. [PMID: 35219511 DOI: 10.1016/j.ultrasmedbio.2022.01.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2021] [Revised: 01/18/2022] [Accepted: 01/21/2022] [Indexed: 06/14/2023]
Abstract
A retrospective single-center study was performed to assess the performance of ultrasound image-based texture analysis in differentiating angiomyolipoma (AML) from renal cell carcinoma (RCC) on incidental hyperechoic renal lesions. Ultrasound reports of patients from 2012 to 2017 were queried, and those with a hyperechoic renal mass <5 cm in diameter with further imaging characterization and/or pathological correlation were included. Quantitative texture analysis was performed using a model including 18 texture features. Univariate logistic regression was used to identify texture variables differing significantly between AML and RCC, and the performance of the model was measured using the area under the receiver operating characteristic (ROC) curve. One hundred thirty hyperechoic renal masses in 127 patients characterized as RCCs (25 [19%]) and AMLs (105 [81%]) were included. Size (odds ratio [OR] = 0.12, 95% confidence interval [CI]: 0.04-0.43, p < 0.001) and 4 of 18 texture features, including entropy (OR = 0.09, 95% CI: 0.01-0.81, p = 0.03), gray-level non-uniformity (OR = 0.12, 95% CI: 0.02-0.72, p = 0.02), long-run emphasis (OR = 0.49, 95% CI: 0.27-0.91, p = 0.02) and run-length non-uniformity (OR = 2.18, 95% CI: 1.14-4.16, p = 0.02) were able to differentiate AMLs from RCCs. The area under the ROC curve for the performance of the model, including texture features and size, was 0.945 (p < 0.001). Ultrasound image-based textural analysis enables differentiation of hyperechoic RCCs from AMLs with high accuracy, which improves further when combined with tumor size.
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Affiliation(s)
- Peiman Habibollahi
- Department of Interventional Radiology, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Laith R Sultan
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Darren Bialo
- Larchmont Imaging Associates, Larchmont, New Jersey, USA
| | - Abdulrahman Nazif
- Department of Internal Medicine, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Nauroze A Faizi
- Department of Radiology, University of Minnesota, Minneapolis, Minnesota, USA
| | - Chandra M Sehgal
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Anil Chauhan
- Department of Radiology, University of Minnesota, Minneapolis, Minnesota, USA.
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Pitfalls in Renal Ultrasound. Ultrasound Q 2020; 36:300-313. [PMID: 33298769 DOI: 10.1097/ruq.0000000000000519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
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.
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Hussain T, Lam V, Farhad M, Lee S, Stephenson JA, Kockelbergh R, Rajesh A. Can subcentimetre ultrasound detected angiomyolipomas be safely disregarded? Clin Radiol 2020; 75:287-292. [PMID: 31916983 DOI: 10.1016/j.crad.2019.12.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Accepted: 12/04/2019] [Indexed: 01/20/2023]
Abstract
AIM To optimise follow-up by dismissing lesions on baseline ultrasound (US) if renal lesions conform to US criteria of an angiomyolipoma (AML). METHOD AND MATERIALS The present study was a 10-year retrospective review of patients who were found to have incidental hyperechoic renal lesions on US to ascertain the outcome from subsequent imaging, clinical encounters, and cancer registrations. Exclusions included renal calculi, tuberous sclerosis, Von-Hippel-Lindau, or a known cancer. RESULTS After excluding 39 patients, 1,493 patients were identified. One hundred and sixty had more than one lesion with 87 patients having bilateral lesions. Regardless of indication, 889 patients had subsequent imaging within 5 years (59.5%). The average size of all AMLs was 13.2 mm. In the group with lesions that were <10 mm (807), 438 had imaging follow-up with an average follow-up time of 1.5 years. Mean lesion size in this group was 7 mm, with an average increase of <0.5 mm on follow-up. No lesions were found to be malignant on subsequent imaging nor did any of these patients have a subsequent renal cancer diagnosis registered at local multidisciplinary team meetings. CONCLUSION No incidental subcentimetre hyperechoic renal lesion with imaging characteristics of an AML demonstrated significant growth or developed into a malignancy on follow-up.
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Affiliation(s)
- T Hussain
- Department of Radiology, University Hospitals of Leicester NHS Trust, Leicester General Hospital, Gwendolen Road, Leicester LE5 4PW, UK
| | - V Lam
- Department of Radiology, University Hospitals of Leicester NHS Trust, Leicester General Hospital, Gwendolen Road, Leicester LE5 4PW, UK
| | - M Farhad
- Department of Radiology, University Hospitals of Leicester NHS Trust, Leicester General Hospital, Gwendolen Road, Leicester LE5 4PW, UK
| | - S Lee
- Department of Radiology, University Hospitals of Leicester NHS Trust, Leicester General Hospital, Gwendolen Road, Leicester LE5 4PW, UK
| | - J A Stephenson
- Department of Radiology, University Hospitals of Leicester NHS Trust, Leicester General Hospital, Gwendolen Road, Leicester LE5 4PW, UK
| | - R Kockelbergh
- Department of Urology, University Hospitals of Leicester NHS Trust, Leicester General Hospital, Gwendolen Road, Leicester LE5 4PW, UK
| | - A Rajesh
- Department of Radiology, University Hospitals of Leicester NHS Trust, Leicester General Hospital, Gwendolen Road, Leicester LE5 4PW, UK.
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