Guideline sources The following summarized guidelines for the evaluation and management of focal nodular hyperplasia (FNH) are prepared by our editorial team based on guidelines from the American College of Radiology (ACR 2020), the European Federation of Societies for Ultrasound (EFSU 2020), the American College of Gastroenterology (ACG 2016; 2014), and the European Association for the Study of the Liver (EASL 2016). 1 2 3 4 5 6 Guidelines 1. Diagnostic investigations Contrast-enhanced ultrasound: As per ACR 2020 guidelines: Obtain contrast-enhanced abdominal ultrasound of an indeterminate > 1 cm liver lesion on initial ultrasound in patients with a normal liver with no suspicion or evidence of extrahepatic malignancy or underlying liver disease. B Obtain contrast-enhanced abdominal ultrasound of an incidental liver lesion > 1 cm on initial ultrasound, non-contrast or single-phase CT, or non-contrast MRI in patients with known chronic liver disease. B https://web.pathway.md/diseases/recJJ43FNQFht1T7R 1/4 6/29/23, 4:06 AM Focal nodular hyperplasia Pathway As per EFSU 2020 guidelines, obtain liver ultrasound using B-mode and Doppler mode before obtaining contrast-enhanced ultrasound to characterize focal liver lesions. B Show 14 more As per EASL 2016 guidelines, obtain contrast-enhanced ultrasound for the diagnosis of FNH (~ 100% specificity with typical imaging features observed in combination). Recognize that the highest diagnostic accuracy by contrast-enhanced ultrasound is achieved in FNH < 3 cm. B Cross-sectional imaging: As per ACR 2020 guidelines, obtain contrast-enhanced multiphase CT, contrast-enhanced MRI, or contrast-enhanced ultrasound of an indeterminate > 1 cm liver lesion on initial ultrasound in patients with a normal liver with no suspicion or evidence of extrahepatic malignancy or underlying liver disease. B Show 7 more As per EASL 2016 guidelines, obtain CT or MRI for the diagnosis of FNH (~ 100% specificity with typical imaging features observed in combination). Recognize that MRI has the highest diagnostic performance overall. B As per ACG 2014 guidelines, obtain MRI or CT for the diagnosis of FNH. B 2. Diagnostic procedures Liver biopsy: do not perform a routine liver biopsy to confirm the diagnosis of FNH. D 3. Medical management Indications for treatment: As per EASL 2016 guidelines, do not offer treatment in patients with FNH. D As per ACG 2014 guidelines, do not offer any therapeutic intervention in patients with asymptomatic FNH. D 4. Specific circumstances Pregnant patients: do not obtain routine imaging or surveillance for asymptomatic FNH during pregnancy. D Patients with hereditary hemorrhagic telangiectasia: suspect FNH in patients with HHT with liver masses, and obtain noninvasive, contrast-enhanced imaging for diagnostic confirmation. B Patients on oral contraceptives: Counsel patients that the use of oral contraceptives is not contraindicated in FNH. B Obtain annual ultrasound for 2-3 years in female patients with FNH wishing to continue the use of oral contraceptives. B https://web.pathway.md/diseases/recJJ43FNQFht1T7R 2/4 6/29/23, 4:06 AM Focal nodular hyperplasia Pathway 5. Patient education General counseling: counsel patients that pregnancy and the use of oral contraceptives or anabolic steroids are not contraindicated in FNH. B 6. Follow-up and surveillance Indications for referral: refer patients with atypical imaging findings or in the presence of symptoms to a benign liver tumor multidisciplinary team. B Serial imaging assessment: As per EASL 2016 guidelines, do not obtain follow-up imaging in patients with a typical lesion of FNH unless there is underlying vascular liver disease. D As per ACG 2014 guidelines: Do not obtain follow-up imaging in patients with a firm diagnosis of FNH unless oral contraceptives are used. D Obtain annual ultrasound for 2-3 years in female patients with FNH wishing to continue the use of oral contraceptives. B Clinical findings Symptoms Past medical history Abdominal pain Budd-chiari syndrome HHT Abdominal exam Hepatic AVM Hepatic adenoma Hepatomegaly Hepatic hemangioma Palpable abdominal mass Imaging findings Hepatic mass with central scar Spoke wheel sign References 1. Marrero JA, Ahn J, Rajender Reddy K et al. ACG clinical guideline: the diagnosis and management of focal liver lesions. Am J Gastroenterol. 2014 Sep;109 9 1328 47. Open 2. Expert Panel on Gastrointestinal Imaging, Victoria Chernyak, Jeanne M Horowitz et al. ACR Appropriateness Criteria Liver Lesion-Initial Characterization. J Am Coll Radiol. 2020 Nov;17 11S S429 S446. Open 3. Tram T Tran, Joseph Ahn, Nancy S Reau. ACG Clinical Guideline: Liver Disease and Pregnancy. Am J Gastroenterol. 2016 Feb;111 2 176 94; quiz 196. Open 4. European Association for the Study of the Liver EASL . EASL Clinical Practice Guidelines on the management of benign liver tumours. J Hepatol. 2016 Aug;65 2 386 98. Open https://web.pathway.md/diseases/recJJ43FNQFht1T7R 3/4 6/29/23, 4:06 AM Focal nodular hyperplasia Pathway 5. European Association for the Study of the Liver. EASL Clinical Practice Guidelines: Vascular diseases of the liver. J Hepatol. 2016 Jan;64 1 179 202. Open 6. Christoph F Dietrich, Christian P llson Nols e, Richard G Barr et al. Guidelines and Good Clinical Practice Recommendations for Contrast-Enhanced Ultrasound CEUS in the Liver-Update 2020 WFUMB in Cooperation with EFSUMB, AFSUMB, AIUM, and FLAUS. Ultrasound Med Biol. 2020 Oct;46 10 2579 2604. Open 7. Monika Sarkar, Carla W Brady, Jaquelyn Fleckenstein et al. Reproductive Health and Liver Disease: Practice Guidance by the American Association for the Study of Liver Diseases. Hepatology. 2021 Jan;73 1 318 365. Open https://web.pathway.md/diseases/recJJ43FNQFht1T7R 4/4