Labra A, Schiappacasse G, Constenla D, Cristi J. Renal angiomyolipomas: Typical and atypical features on computed tomography and magnetic resonance imaging. World J Radiol 2025; 17(2): 104282 [PMID: 40060953 DOI: 10.4329/wjr.v17.i2.104282]
Corresponding Author of This Article
Joaquin Cristi, MD, Departamento de Imágenes, Facultad de Medicina Clínica Alemana-Universidad del Desarrollo, Avenida Vitacura 5951, Vitacura, Santiago 7650568, Región Metropolitana, Chile. jcristip@udd.cl
Research Domain of This Article
Radiology, Nuclear Medicine & Medical Imaging
Article-Type of This Article
Minireviews
Open-Access Policy of This Article
This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
World J Radiol. Feb 28, 2025; 17(2): 104282 Published online Feb 28, 2025. doi: 10.4329/wjr.v17.i2.104282
Renal angiomyolipomas: Typical and atypical features on computed tomography and magnetic resonance imaging
Andres Labra, Giancarlo Schiappacasse, Diego Constenla, Joaquin Cristi
Andres Labra, Giancarlo Schiappacasse, Diego Constenla, Joaquin Cristi, Departamento de Imágenes, Facultad de Medicina Clínica Alemana-Universidad del Desarrollo, Santiago 7650568, Región Metropolitana, Chile
Author contributions: All the authors listed above contributed to the conception, design, analysis of the literature, writing or critical review of the article and approval of the final version of the manuscript.
Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article.
Open Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Joaquin Cristi, MD, Departamento de Imágenes, Facultad de Medicina Clínica Alemana-Universidad del Desarrollo, Avenida Vitacura 5951, Vitacura, Santiago 7650568, Región Metropolitana, Chile. jcristip@udd.cl
Received: December 17, 2024 Revised: January 24, 2025 Accepted: February 18, 2025 Published online: February 28, 2025 Processing time: 72 Days and 6 Hours
Abstract
Angiomyolipomas (AMLs) represent the most common benign solid renal tumors. The frequency of their detection in the general population is increasing owing to advances in imaging technology. The objective of this review is to discuss computed tomography (CT) and magnetic resonance imaging findings for both typical and atypical renal AMLs, along with their associated complications. AMLs are typically defined as solid triphasic tumors composed of varying amounts of dysmorphic and tortuous blood vessels, smooth muscle components and adipose tissue. In an adult, a classical renal AML appears as a solid, heterogeneous renal cortical mass with macroscopic fat. However, up to 5% of AMLs contain minimal fat and cannot be reliably diagnosed by imaging. Fat-poor AMLs can appear as hyperattenuating masses on unenhanced CT and as hypointense masses on T2WI; other AMLs may be isodense or exhibit cystic components. Hemorrhage is the most common complication, and AMLs with hemorrhage can mimic other tumors, making their diagnosis challenging. Understanding the variable and heterogeneous nature of this neoplasm to correctly classify renal AMLs and to avoid misdiagnosis of other renal lesions is crucial.
Core Tip: Angiomyolipomas can be differentiated into triphasic benign angiomyolipomas (AMLs) and potentially aggressive epithelial AMLs. Triphasic AMLs can be further subdivided into classical fat-rich AMLs and fat-poor AMLs. Fat-poor AMLs can be hyperattenuating, isoattenuating or hyperattenuating with an epithelial cystic component. Recognition of the different imaging characteristics of AML types on computed tomography and magnetic resonance imaging is fundamental for differentiating this disease from other renal neoplasms.
