Hepatocellular adenoma

Hepatocellular adenoma
File:Hepatic adenoma low mag.jpg Micrograph of a hepatic adenoma (bottom of image). H&E stain.
Classification and external resources
Specialty
ICD-O	M8170/0
DiseasesDB	5726
eMedicine	med/48
Patient UK	Hepatocellular adenoma
MeSH	D018248

Hepatocellular adenoma, also hepatic adenoma, or rarely hepadenoma, is an uncommon benign liver tumor which is associated with the use of hormonal contraception with a high estrogen content. Patients taking higher potency hormones, patients of advanced age, or patients with prolonged duration of use have a significantly increased risk of developing hepatocellular adenomas.

Signs and Symptoms

About 25-50% of hepatic adenomas cause pain in the right upper quadrant or epigastric region of the abdomen. Since hepatic adenomas can be large (8–15 cm), patients may notice a palpable mass. However, hepatic adenomas are usually asymptomatic, and may be discovered incidentally on imaging ordered for some unrelated reason. If not treated, there is a 30% risk of bleeding. Bleeding may lead to hypotension, tachycardia, and sweating (diaphoresis).

Diagnosis

It is important to distinguish hepatic adenoma from other benign liver tumors, such as hemangiomas and focal nodular hyperplasia, because hepatic adenomas have a small but meaningful risk of progressing into a malignancy. MRI is the most useful investigation in the diagnosis and work-up. A poly-phasic CT scan is another useful test for diagnosing hepatic adenoma.

Large hepatic adenomas have a tendency to rupture and bleed massively inside the abdomen.

Radiologic differential diagnosis

• Echinococcal cyst
• Focal fatty change
• Focal nodular hyperplasia
• Hepatoblastoma
• Infiltrative liver disease
• Inflammatory pseudotumor
• Leiomyosarcoma
• Lymphoma
• Nodular regenerative hyperplasia

Pathologic diagnosis

File:Hepatic adenoma high mag reticulin.jpg

Micrograph of a hepatic adenoma demonstrating a regular reticulin scaffold. Reticulin stain.

Hepatic adenomas are, typically, well-circumscribed nodules that consist of sheets of hepatocytes with a bubbly vacuolated cytoplasm. The hepatocytes are on a regular reticulin scaffold and less or equal to three cell thick.

The histologic diagnosis of hepatic adenomas can be aided by reticulin staining. In hepatic adenomas, the reticulin scaffold is preserved and hepatocytes do not form layers of four or more hepatocytes, as is seen in hepatocellular carcinoma.

Cells resemble normal hepatocytes and are traversed by blood vessels but lack portal tracts or central veins.

Etiology

Ninety percent of hepatic adenomas arise in women aged 20–40, most of whom use oral contraceptives.

Related Conditions

Hepatic adenomas are related to glycogen storage diseases, type 1, as well as anabolic steroid use.

Treatment

Some authors feel that all hepatocellular adenoma should be resected, because of the risk of rupture causing bleeding and because they may contain malignant foci. Current recommendations are that all hepatic adenomas should be resected, as long as they are surgically accessible and the patient is a reasonable operative candidate. Patients with adenomas should avoid oral contraceptives or hormonal replacement therapy.

Pregnancy could cause the adenoma to grow faster, so patients with hepatic adenomas should avoid pregnancy.

Additional images

• Hepatic adenoma high mag.jpg

  Micrograph of hepatic adenoma. H&E stain.

• Hepatic adenoma low mag reticulin.jpg

  Micrograph of hepatic adenoma. Reticulin stain.

External links

• University of Utah - Pathology Images