Sporadic Renal Angiomyolipoma: Can We Adopt a Uniform Management Protocol?

Abstract

Renal angiomyolipomas (AMLs), formerly known as PEComas (tumors showing perivascular epithelioid cell differentiation) are common benign renal masses composed of a varying ratio of fat, blood vessels, and smooth muscles. They are largely asymptomatic and diagnosed incidentally on imaging.

The adipose tissue content is the factor that gives AMLs their characteristic appearance on imaging and makes them easily identifiable. However, the fat-poor or fat-invisible varieties, which are difficult to differentiate radiologically from renal cell carcinomas (RCCs), present a diagnostic challenge. It is thus essential to establish the diagnosis and identify the atypical and hereditary cases as they require more intense surveillance and management due to their potential for malignant transformation.

Multiple management options are available, ranging from conservative approach to embolization and to the more radical option of nephrectomy. While the indications for intervention are relatively clear and aimed at a rather small cohort, the protocol for follow-up of the remainder of the cohort forming the majority of cases is not well established. The surveillance and discharge policies therefore vary between institutions and even between individual practitioners. We have reviewed the literature to establish an optimum management pathway focusing on the typical AMLs.

Resumen

Los angiomiolipomas renales (AML), antes conocidos como PEComas (tumores que muestran epitelioides perivasculares) son masas renales benignas frecuentes compuestas por una proporción variable de grasa, vasos sanguíneos y músculos lisos. Suelen ser asintomáticos y se diagnostican de forma incidental en las pruebas de imagen. El contenido de tejido adiposo es el factor que confiere a los AML su aspecto característico en las imágenes y los hace fácilmente identificables. Sin embargo, las variedades pobres en grasa o invisibles, que son difíciles de diferenciar radiológicamente de los carcinomas de células renales (CCR), suponen un reto diagnóstico. Por lo tanto, es esencial establecer el diagnóstico e identificar los casos atípicos y hereditarios, ya que requieren una vigilancia y un tratamiento más intensos debido a su potencial de malignización. debido a su potencial de transformación maligna. Existen múltiples opciones de tratamiento, que van desde el enfoque conservador hasta la embolización y la opción más radical de la nefrectomía. Si bien las indicaciones para la intervención son relativamente claras y están dirigidas a una cohorte bastante pequeña, el protocolo para el seguimiento del resto de la cohorte que forma la mayoría de los casos no está bien establecido. Por lo tanto, las políticas de vigilancia y alta varían entre instituciones e incluso entre profesionales individuales. Hemos revisado la literatura para establecer una ruta de manejo óptima centrada en los AML típicos.

Keywords

renal angiomyolipoma - AML - management - guideline

Palabras Clave

angiomiolipoma renal - AML - manejo - guía

Publication History

Received: 11 May 2022

Accepted: 20 September 2022

Article published online:
28 December 2022

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