Hepatic adenoma is an uncommon benign liver tumour that is hormone induced. The tumours have a predilection to haemorrhage and must be differentiated from other focal liver lesions. They are usually solitary (70-80% of cases 10) but when multiple the condition is known as hepatic adenomatosis (usually >10 adenomas 9). Multiple lesions are frequently observed in patients with type I glycogen storage disease 10.
It is the most frequent hepatic tumour in young women who are on the oral contraceptive pill. They are also found in a number of other situations including 3:
- oral contraceptive use: most common association
- anabolic steroids: typically young men
- type I glycogen storage disease (von Gierke's disease)
The lesions typically remain asymptomatic until they spontaneously rupture, at which time the patient develops abdominal pain. Occasionally rapid bleeding into the peritoneal cavity can lead to exsanguination and death.
Histologically, hepatic adenomas are characterised by proliferation of pleomorphic hepatocytes without normal lobular architecture. These cells frequently have abundant glycogen (thus the von Gierke's disease link) 5. They are traditionally described as being devoid of bile ducts and of Kupffer cells, although this has been shown not to be the case, with diminished number of Kupffer cells found in many cases 1,3-4. This has important implication in Tc99m sulphur colloid scans (see below)
The lesion is well circumscribed, often subcapsular with a yellow colouration on account of frequently abundant fat and lack of bile. Haemorrhagic change is common. The tumour may be surrounded by a fibrous pseudocapsule 15.
There are four subtypes of hepatic adenoma 17:
- inflammatory hepatic adenoma
- HNF 1alpha mutated hepatic adenoma
- beta catenin-mutated hepatic adenoma
- unclassified hepatocellular adenoma
Hepatic adenomas are usually solitary and large at the time of diagnosis (5-15 cm) 3,13. They are most frequently seen at a subcapsular location in right lobe of liver and are often a round well-defined pseudo-encapsulated mass. Occasional dystrophic calcification may be present.
The attenuation of these tumours is variable, depending on 8:
- fresh haemorrhage: may be hyperattenuating
- fat content may make the mass hypoattenuating
In general they are well marginated and iso-attenuating to liver. On contrast administration they demonstrate transient relatively homogenous enhancement returning to near isodensity on portal venous and delayed phase image 8,10.
If the rest of the liver shows diffuse fatty infiltration then they will appear hyperattenuating.
Calcification may be seen in areas of old haemorrhage (5-10% of cases 10) .
A hepatic adenoma usually presents as a solitary well-demarcated heterogeneous mass. Echogenicity is variable 3:
- hypoechoic: 20-40%
- hyperechoic: up to 30%, often due to fat 3,8
A hypoechoic halo of focal fat sparing is also frequently seen.
- colour Doppler: may show perilesional sinusoids
- contrast-enhanced ultrasound 16:
- arterial phase:
- hypervascular (similar to FNH, although adenomas are usually less enhancing)
- portal venous and delayed phases:
- centripetal filling in (opposite of FNH)
- arterial phase:
In non-haemorrhagic adenomas, they typically appear as:
- variable and can range from being hyper-, iso-, to hypointense
- hyperintense: 35-77% cases 8
- variable and can range from being hyper-, iso-, to hypointense
- mildly hyperintense: 47-74% 2,8
- presence of fat typically leads to signal drop out on out-of-phase imaging
T1 C+ (Gd)
- on the dynamic postcontrast sequence, adenomas show early arterial enhancement and become nearly isointense relative to liver on delayed images 10
- some report suggest that the enhancement becomes isointense to the rest of the liver by 1 minute 6
- T1 C+ (Eovist): adenomas usually appear hypointense on hepatocellular phase due to reduced uptake of Gd-EOB-DTPA/Eovist 14.
If haemorrhagic, then blood products may lead to significant heterogeneity in signal on all sequences.
Although classically described as a focal photopenic lesion on Tc99m sulphur colloid scans with surrounding rim of increased uptake, uptake may be seen in up to 23% of cases 1. This is accounted for by the presence of Kupffer cells in many adenomata, even though they may be reduced in number.
Usually has increased activity on a HIDA scan, but does not take up gallium on a gallium scan.
- spontaneous rupture
- although uncommon, hepatic adenomas do rarely degenerate into hepatocellular carcinomas (HCC) 8
Treatment and prognosis
Usually they are benign but there is a very small risk of transformation to hepatocellular carcinoma (HCC).
In general, and if feasible, adenomas are resected, both to eliminate the risk of spontaneous rupture and to conclusively confirm the diagnosis 7. In cases where the lesion is small and not subcapsular, and has a typical appearance, some would choose to observe (with imaging and alpha fetoprotein levels) and cease oral contraceptives. In such instances the adenoma may regress. In inoperable cases, hepatic arterial embolisation may have a role 7.
General imaging differential considerations include:
hepatocellular carcinoma (HCC)
- washout tends to leave the lesion hypointense c.f. to rest of liver
- different demographics
- may be difficult to distinguish if well differentiated 7
fibrolamellar hepatocellular carcinoma
- radiating/central scar
- calcification more common 8
- lymph node enlargement common
focal nodular hyperplasia (FNH)
- T2: bright central scars that have late enhancement
- US: may be difficult to differentiate adenoma from FNH on nonenhanced ultrasound
liver metastases (hypervascular)
- usually hypointense on T1, and moderately hyperintense on T2
- fat and haemorrhage are less common
- haemangioma of the liver
Liver and intrahepatic bile duct tumours
- benign epithelial tumours
- hepatic regenerative nodule
- focal nodular hyperplasia
- hepatocellular adenoma
- hepatic/biliary cysts
- hepatocellular hyperplasia
- benign nonepithelial tumours
- primary malignant epithelial tumours
- primary malignant nonepithelial tumours
- hematopoeietic and lymphoid tumours
- secondary tumours
- hepatic mesenchymal hamartoma
- nodular regenerative hyperplasia
- inflammatory myofibroblastic tumor (inflammatory pseudotumor)
- hepatic solitary fibrous tumour
- hepatic teratoma
- hepatic yolk sac tumour
- hepatic Kaposi sarcoma
- hepatic lipoma
- adrenal rest tumours
- pancreatic rest tumours
- primary hepatic carcinoid
- hepatic fibroma
- hepatic myxoma
- hepatic rhabdoid tumour
- 1. Lubbers PR, Ros PR, Goodman ZD et-al. Accumulation of technetium-99m sulfur colloid by hepatocellular adenoma: scintigraphic-pathologic correlation. AJR Am J Roentgenol. 1987;148 (6): 1105-8. AJR Am J Roentgenol (abstract) - Pubmed citation
- 2. Gebel M. Ultrasound in gastroenterology and hepatology. Wiley-Blackwell. (2000) ISBN:0632055286. Read it at Google Books - Find it at Amazon
- 3. McGahan JP, Goldberg BB. Diagnostic ultrasound. Informa Health Care. (2008) ISBN:1420069780. Read it at Google Books - Find it at Amazon
- 4. Lee JK. Computed body tomography with MRI correlation. Lippincott Williams & Wilkins. (2006) ISBN:0781745268. Read it at Google Books - Find it at Amazon
- 5. Rubin R, Strayer DS, Rubin E. Rubin's Pathology, clinicopathologic foundations of medicine. Lippincott Williams & Wilkins. (2008) ISBN:0781795168. Read it at Google Books - Find it at Amazon
- 6. Semelka RC. Abdominal-pelvic MRI. Wiley. (2006) ISBN:0471692735. Read it at Google Books - Find it at Amazon
- 7. Doherty GM, Way LW. Current surgical diagnosis & treatment. McGraw-Hill Medical. (2006) ISBN:007142315X. Read it at Google Books - Find it at Amazon
- 8. Grazioli L, Federle MP, Brancatelli G et-al. Hepatic adenomas: imaging and pathologic findings. Radiographics. 21 (4): 877-92. Radiographics (full text) - Pubmed citation
- 9. Giovanoli O, Heim M, Terracciano L et-al. MRI of hepatic adenomatosis: initial observations with gadoxetic acid contrast agent in three patients. AJR Am J Roentgenol. 2008;190 (5): W290-3. doi:10.2214/AJR.07.3198 - Pubmed citation
- 10. Faria SC, Iyer RB, Rashid A et-al. Hepatic adenoma. AJR Am J Roentgenol. 2004;182 (6): 1520. AJR Am J Roentgenol (full text) - Pubmed citation
- 11. Kim TK, Jang HJ, Burns PN et-al. Focal nodular hyperplasia and hepatic adenoma: differentiation with low-mechanical-index contrast-enhanced sonography. AJR Am J Roentgenol. 2008;190 (1): 58-66. doi:10.2214/AJR.07.2493 - Pubmed citation
- 12. Kume N, Suga K, Nishigauchi K et-al. Characterization of hepatic adenoma with atypical appearance on CT and MRI by radionuclide imaging. Clin Nucl Med. 1997;22 (12): 825-31. Clin Nucl Med (link) - Pubmed citation
- 12. Hussain SM, Van den bos IC, Dwarkasing RS et-al. Hepatocellular adenoma: findings at state-of-the-art magnetic resonance imaging, ultrasound, computed tomography and pathologic analysis. Eur Radiol. 2006;16 (9): 1873-86. doi:10.1007/s00330-006-0292-4 - Pubmed citation
- 13. Horton KM, Bluemke DA, Hruban RH et-al. CT and MR imaging of benign hepatic and biliary tumors. Radiographics. 19 (2): 431-51. Radiographics (full text) - Pubmed citation
- 14. Campos JT, Sirlin CB, Choi JY. Focal hepatic lesions in Gd-EOB-DTPA enhanced MRI: the atlas. Insights Imaging. 2012;doi:10.1007/s13244-012-0179-7 - Pubmed citation
- 15. Arrivé L, Fléjou JF, Vilgrain V et-al. Hepatic adenoma: MR findings in 51 pathologically proved lesions. Radiology. 1994;193 (2): 507-12. doi:10.1148/radiology.193.2.7972769 - Pubmed citation
- 16. Malhi H, Grant EG, Duddalwar V. Contrast-Enhanced Ultrasound of the Liver and Kidney. Radiol. Clin. North Am. 2014;52 (6): 1177-1190. doi:10.1016/j.rcl.2014.07.005 - Pubmed citation
- 17. Katabathina VS, Menias CO, Shanbhogue AK et-al. Genetics and imaging of hepatocellular adenomas: 2011 update. Radiographics. 2011;31 (6): 1529-43. doi:10.1148/rg.316115527 - Pubmed citation
Synonyms & Alternative Spellings
|Synonyms or Alternative Spelling||Include in Listings?|
|Adenoma of liver||✗|