Abstract

Asymptomatic athlete with persistently elevated enzymes and liver stiffness on 2D-SWE. Liver biopsy revealed discrete sinusoidal dilatation and centrilobular fibrosis, without portoportal fibrosis. Extrahepatic factors, such as systemic venous dilation from chronic intense exercise, can increase liver stiffness and liver enzymes without chronic liver disease.

CLINICAL HISTORY

55-year-old woman, marathon runner, with a routine of intense daily exercise for several years. BMI 18.7 kg/m², with persistent elevation of transaminases (<2x upper reference value) for at least 8 years, without evidence of viral, autoimmune, or biliary diseases, nor a history of alcohol or hepatotoxic drug use.

IMAGING FINDINGS

Ultrasound examinations performed annually since 2017 demonstrate dilation of the inferior vena cava and hepatic veins, with preserved respiratory caliber variation, and no signs of cardiopathy. B-mode ultrasonography of the liver shows no remarkable parenchymal abnormalities, except for dilatation of the hepatic veins and inferior vena cava with reduced respiratory variation. Splenic longitudinal axis measures 76mm.

DISCUSSION

Persistent elevation of transaminases in asymptomatic individuals often prompts an investigation for chronic liver diseases. Two-dimensional shear wave elastography (2D-SWE) is a validated technique for estimating liver stiffness, typically associated with clinically significant portoportal fibrosis (1-3). However, extrahepatic factors-such as systemic venous congestion-may influence liver stiffness (4). Systemic venous congestion affects zone 3 of the hepatic acinus, causing sinusoidal dilatation and centrilobular fibrosis. These alterations can result in elevated liver enzymes and increased liver stiffness, even in the absence of portoportal fibrosis on histology (5). Typically, hepatic venous congestion is secondary to cardiac conditions such as congestive heart failure or tricuspid regurgitation. In this case, however, the patient is a female athlete with a long-standing, high-volume training regimen. Serial ultrasonography revealed dilation of the inferior vena cava and hepatic veins, with preserved respiratory variation in caliber and no evidence of cardiac disease. Liver stiffness was mildly to moderately increased on 2D-SWE, and liver biopsies demonstrated discrete sinusoidal dilatation and centrilobular fibrosis, without portoportal fibrosis. These findings are consistent with hepatic venous congestion associated with cardiovascular overload. Previous studies by Goldhammer et al. (6) and D’Ascenzi et al. (7) have demonstrated that inferior vena cava dilation is present in 95% of elite athletes and correlates positively with maximal VO₂ and right ventricular dimensions. These changes reflect extracardiac structural adaptations to chronic intense exercise. Teichgräber et al. (6) further demonstrated that physical exercise increases hepatic venous flow through both augmented hepatic arterial flow and tricuspid regurgitation. These physiological adaptations may lead to centrilobular vein congestion, sinusoidal dilatation, and centrilobular fibrosis-distinct from the portoportal fibrosis typically seen in chronic fibrosing liver diseases and cirrhosis. This case underscores the importance of correlating imaging findings with the clinical context, thereby avoiding misdiagnosis of chronic fibrosing liver disease and unnecessary invasive procedures Liver elastography (2D-SWE) showed median stiffness of 9.7 kPa (1.8 m/s) in 2017 (Supersonic Aixplorer), 9.7 kPa (1.8 m/s) in 2021, and 7.0 kPa in 2022 (Canon Aplio i600). All measurements had an IQR/median ratio below 0.30 (Figure 1). A liver biopsy performed on 03/10/2017 revealed centrilobular sinusoidal congestion and discrete perisinusoidal and perivenular fibrosis, without portoportal fibrosis. The patient remains asymptomatic, in good general health, maintaining a routine of intense daily physical exercise.

DIFFERENTIAL DIAGNOSIS

• Chronic liver disease (viral, autoimmune, alcoholic)

• Storage liver diseases (hemochromatosis)

• Chronic cholangiopathy,

• Amyloidosis.

TEACHING POINTS

This case is unprecedented in the literature, as the relationship between liver changes resulting from long-term intense physical exercise and hepatic structure has not yet been addressed. Recently, a better understanding of sinusoidal diseases has clarified the hepatic alterations observed in chronic cardiopathies and hepatic venous thrombosis. Similar, albeit less pronounced, changes are present in high-performance athletes, in whom elevated liver enzymes and liver stiffness, in the absence of other clinical conditions and with a normal liver ultrasound, are consistent with the so-called “athlete’s liver” (a term we introduce in this article).

REFERENCES

1. Barr RG, Wilson SR, Rubens D, Garcia-Tsao G, Ferraioli G. Update to the Society of Radiologists in Ultrasound Liver Elastography Consensus Statement. Radiology. agosto de 2020;296(2):263-74.

2. Dietrich CF, Bamber J, Berzigotti A, Bota S, Cantisani V, Castera L, et al. EFSUMB Guidelines and Recommendations on the Clinical Use of Liver Ultrasound Elastography, Update 2017 (Long Version). Ultraschall Med Stuttg Ger 1980. agosto de 2017;38(4):e16-47.

3. Ferraioli G, Wong VWS, Castera L, Berzigotti A, Sporea I, Dietrich CF, et al. Liver Ultrasound Elastography: An Update to the World Federation for Ultrasound in Medicine and Biology Guidelines and Recommendations. Ultrasound Med Biol. 1o de dezembro de 2018;44(12):2419-40.

4. Ferraioli G, Barr RG. Ultrasound liver elastography beyond liver fibrosis assessment. World J Gastroenterol. 28 de junho de 2020;26(24):3413-20.

5. Venkatesh SK, Harper KC, Borhani AA, Furlan A, Thompson SM, Chen EZM, et al. Hepatic Sinusoidal Disorders. RadioGraphics. setembro de 2024;44(9):e240006.

6. Goldhammer E, Mesnick N, Abinader EG, Sagiv M. Dilated inferior vena cava: a common echocardiographic finding in highly trained elite athletes. J Am Soc Echocardiogr Off Publ Am Soc Echocardiogr. novembro de 1999;12(11):988-93.

7. D’Ascenzi F, Cameli M, Padeletti M, Lisi M, Zacà V, Natali B, et al. Characterization of right atrial function and dimension in top-level athletes: a speckle tracking study. Int J Cardiovasc Imaging. janeiro de 2013;29(1):87-94.

FIGURES

Figure 1: (A-C) Ultrasound and 2D-SWE performed on 02/10/2017: A) ectatic inferior vena cava; B) elastographic measurements in the right hepatic lobe; C) right subcostal view showing hepatic hilum and portal bifurcation. (D-G) Ultrasound and 2D-SWE performed on June 2, 2021: D) subcostal view showing liver and portal bifurcation; E) 2D-SWE in the right hepatic lobe; F) propagation map; and (G) elastographic measurements.

Article receive on Sunday, May 25, 2025

Artigo aprovado em Tuesday, October 28, 2025