Hepatocellular adenoma overview: Difference between revisions
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===Physical Examination=== | ===Physical Examination=== | ||
There are no specific physical examination findings associated with hepatocellular adenoma. | |||
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An elevated concentration of serum alkaline phosphatase and gamma glutamyl transferase may be present in patients with Hepatocellular adenoma.<ref name=fgh>Clinical and laboratory findings of Hepatic adenoma. Scielo 2015. http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-67202013000300012&lng=en&nrm=iso&tlng=en. Accessed on October 16, 2015</ref> | An elevated concentration of serum alkaline phosphatase and gamma glutamyl transferase may be present in patients with Hepatocellular adenoma.<ref name=fgh>Clinical and laboratory findings of Hepatic adenoma. Scielo 2015. http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-67202013000300012&lng=en&nrm=iso&tlng=en. Accessed on October 16, 2015</ref> | ||
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-In-Chief: Cafer Zorkun, M.D., PhD. Zahir Ali Shaikh, MD[2]
Overview
The hepatocellular adenoma is an uncommon benign liver adenoma that is most commonly associated with oral contraceptive use in women of childbearing age. It was first described by Edmondson in 1958 as an encapsulated liver tumor that does not contain bile ducts. In 1970s several case series supported the hypothesis of an association between oral contracptives and hepatocellular adenoma. It is generally asymptomatic, the typical clinical manifestations include spontaneous rupture or hemorrhage leading to acute abdominal pain with progression to hypotension and even death. There are no specific physical examination findings associated with adenoma. The liver function tests and serum tumor markers are usually normal, but may be raised secondary to necrosis or hemorrhage and alkaline phosphatase may be raised in hepatocellular adenomatosis. Th causes of hepatocellular adenoma include; oral contraceptive medications, long term anabolic androgenic steroids, obesity, metabolic syndrome and glycogen storage diseases. It is more commonly seen in western countries where they are exposed to higher doses of oral contraceptive medications. The estimated incidence is 3 per 1,000,000/year and is 3 to 4 per 100,000 with long term oral contraceptive use. The hepatocellular adenomas are classified on the basis of molecular patterns called phenotypic genotypic classification into 04 groups including; HNF1 alpha inactivated adenoma, beta catenin activated adenoma, inflammatory hepatic adenoma and unclassified type adenoma. The exact pathogenesis of hepatocellualr adenoma is still unknown, however, its association with oral contraceptive use is well established. The other associations of adenoma include; long term use of anabolic androgenic steroids and glycogen storage diseases as well. It has been linked to mutations in HNF1a and beta catenin genes. On gross pathology, the hepatocellular adenoma appears as solitary or multiple, unencapsulated and well demarcated lesion, which can occasionally be pedunculated or encapsulated that can also form multiple masses. The intra tumoral hemorrhage can give rise to soft, necrotic, red brown lesion on gross appearance. The microscopic features of hepatocellular adenoma include benign hepatocytes arranged in mildly thickened cell plates with a preserved reticulin network and thin walled arteries. The arteries and arterioles are not accompanied by other portal tract elements such as bile ducts, portal veins or fibroconnective tissue. The hepatocellular adenoma must be differentiated from focal nodular hyperplasia, large regenerative hyperplasia, hepatocellular carcinoma in noncirrhotic patients & fibrolamellar hepatocellular carcinoma, cholangiocarcinoma and metastases. If left untreated, there is 30% bleeding risk. Complications include; bleeding, rupture and malignant transformation. The CT scan findings of heaptocellular adenoma include; non lobulated, well marginated mass that can be encapsulated and rarely calcified and heterogeneous hyperattenuating area within the tumor seen in necrosis or old hemorrhage. The MRI findings include; from hyperintense to mildly hypointense relative to the liver tissue on T1 weighted images. On T2 weighted images they are predominantly hyperintense relative to the liver, whereas in the presence of necrosis or hemorrhage they can be heterogeneous with hyper or hypoattenuating signal. The gold standard method for diagnosis of hepatocellular adenoma is excision biopsy of the liver lesions either by surgery or laparoscopically. There is no specific medical therapy for the adenoma, wait & watch policy is recommended for hepatocellualar adenomas <5 cm following cessation of oral contraceptives. Annual followup with MRI or ultrasound is recommended until menopause. Surgical resection is the treatment of choice for adenomas that are >5 cm in diameter, that increase in size, lesions with intra tumoral hemorrhage and male patients (irrespective of the adenoma size). The radiofrequency ablation (RFA) and trascathter arterial embolization (TAE) may be tried in patients who are poor candidates for surgery.
Historical Perspective
Hepatocellular adenoma was first described in 1958 by Edmondson as an encapsulated liver tumor that does not contain bile ducts. Baum reported the important relationship between the oral contraceptive use and hepatocellular adenoma development in 1973. Edmondson in 1976 published a case control study giving further evidence of this association.
Classification
The hepatocellular adenomas are classified on the basis of molecular patterns called phenotypic-genotypic classification into 04 major groups including; HNF1 alpha inactivated adenoma, beta catenin activated adenoma, inflammatory hepatic adenoma and unclassified type adenoma.
Pathophysiology
The exact pathogenesis of hepatocellular adenoma is still unknown, however, its association with oral contraceptive use is well established. It has also been associated with long term use of anabolic androgenic steroids and glycogen storage diseases. The hepatocellular adenoma have been linked to mutations in HNF1a and beta catenin genes. On gross pathology it appears as a solitary or multiple, unencapsulated and well demarcated mass lesion, which can occasionally be pedunculated or encapsulated that can also form multiple masses. The intratumoral hemorrhage can give rise to soft, necrotic, red brown lesion on gross appearance. The microscopic features of hepatocellular adenoma include benign hepatocytes arranged in mildly thickened cell plates, with a preserved reticulin network and this walled arteries. The arteries and arterioles are not accompanied by other portal tract elements such as bile ducts, portal veins or fibroconnective tissue.
Causes
The causes of hepatocellular adenoma include; oral contraceptive medications, pregnancy, long term use of anabolic androgenic steroids, maturity onset diabetes of young, metabolic syndrome, obesity, glycogen storage diseases, clomiphene and vascular disorders like portal vein agenesis, budd chiari syndrome and hereditary hemorrhagic telangiectasia.
Epidemiology and Demographics
The hepatocellular adenoma is more common in women in western countries where they are exposed to higher doses of oral contraceptives. The estimated incidence is 3 per 1,000,000/year and is 3 to 4 per 100,000 with long term oral contraceptive use. It is more common in women of childbearing age who take oral contraceptives and can rarely occur in men who take long term anabolic androgenic steroids.
Risk factors
The most important risk factor in the development of haptocellular adenoma is use of oral contraceptive medications. Other risk factors include; glycogen storage diseases, familial adenomatous polyposis, klinefelters syndrome, metabolic syndrome, obesity, long term use of anabolic androgenic steroids, vascular disorders such as portal vein agenesis, budd chiari syndrome and hereditary hemorrhagic telangiectasia.
Screening
There is insufficient evidence to recommend any screening test for the hepatocellular adenoma.
Differentiating Hepatocellular adenoma from other Diseases
The hepatocellular adenoma must be differentiated from focal nodular hyperplasia, large regenerative hyperplasia, hepatocellular carcinoma in non cirrhotic patients and fibrolamellar hepatocellular carcinoma, cholangiocarcinoma, primary lymphoma and metastases on the basis of clinical presentation and MRI findings.
Natural History, Complications and Prognosis
There is 30% bleeding risk for hepatocellular adenoma if left untreated. The natural course of hepatocellular adenoma after cessation of oral contraceptive use remains unclear, it may regress or remain stable in size. Complications include bleeding, rupture and malignant transformation. The prognosis is usually good after discontinuation of oral contraceptives, as it may regress. In cases where it does not regress after oral contraception withdrawal, surgery is the management of choice.
Diagnosis
History and Symptoms
The small hepatocellular adenoma is generally asymptomatic. Typical clinical manifestations include spontaneous rupture or hemorrhage leading to acute abdominal pain with progression hypotension and even death. There is history of oral contraceptive use in women and long term anabolic steroids use in men.
Physical Examination
There are no specific physical examination findings associated with hepatocellular adenoma.
Laboratory Findings
An elevated concentration of serum alkaline phosphatase and gamma glutamyl transferase may be present in patients with Hepatocellular adenoma.[1]
Chest X Ray
There are no chest x-ray findings associated with hepatocellular adenoma.
CT
MRI
Ultrasound
Other Imaging Findings
Other Diagnostic Studies
Treatment
Medical Therapy
Surgery
All hepatocellular adenoma should be surgically resected, because of the risk of rupture causing bleeding and because they may contain malignant foci.[2]
Primary Prevention
Secondary Prevention
References
- ↑ Clinical and laboratory findings of Hepatic adenoma. Scielo 2015. http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-67202013000300012&lng=en&nrm=iso&tlng=en. Accessed on October 16, 2015
- ↑ Toso C, Majno P, Andres A, Rubbia-Brandt L, Berney T, Buhler L, Morel P, Mentha G (2005). "Management of hepatocellular adenoma: solitary-uncomplicated, multiple and ruptured tumors". World J Gastroenterol. 11 (36): 5691–5. PMID 16237767.Full text