Hepatomegaly

ALSO KNOWN AS: Fatty liver, enlarged liver

RELATED CONDITIONS: Hepatitis, alcoholic cirrhosis, hepatocellular carcinoma (HCC)

DEFINITION: Hepatomegaly is a potentially reversible symptom of an underlying disease or condition in which the size of the liver (about nine centimeters (cm) in women and less than twelve cm in men) is abnormally increased as estimated by the amount of the liver’s edge below the lower edge of the ribs (costal margin).

Risk factors: Hepatomegaly, commonly known as an enlarged liver, can be caused by alcoholism (early stages), hepatocellular carcinoma (HCC, or primary liver cancer), nonalcoholic fatty liver disease, cirrhosis of the liver, chronic heart failure, infection with hepatitis (A, B, or C), a protein deficiency, diabetes, obesity, starvation, endocrine disorders (Cushing syndrome), and many chronic diseases with nutrition or absorption problems. Other risk factors include corticosteroid use and exposure to aflatoxins, parasites, antibiotics (tetracyclines), contraceptive steroids, halothane, arsenic, thorium, and yellow phosphorus.

Etiology and the disease process: Liver cells perform some of the most important biochemical functions, such as detoxicating ammonia and foreign chemicals and destroying and synthesizing carbohydrates, proteins, amino acids, hormones, fatty acids, glycerides, cholesterol, bile salts, heme, and porphyrin. A problem with one or more metabolic functions can lead to structural and functional abnormalities.

Liver cells respond in various ways to etiologic agents to become enlarged. Pathophysiologic mechanisms include inflammation, excessive storage, infiltrations, congestion, and obstruction. Examples include dilated hepatic sinusoids (due to heart failure), persistently high venous pressure causing liver congestion (in chronic obstructive pancreatitis), dysfunction and enlargement of hepatocytes (during hepatitis), fatty infiltration of parenchymal cells causing fibrosis (in cirrhosis), distension of liver cells (in alcoholism), fatty degeneration and infiltration of hepatocytes (diabetes mellitus, alcoholism, amyloid or glycogen storage), hyperplasia (cirrhoses or hepatomas) leading to sarcoma (metastic carcinoma), and tenderness (congestive heart failure and infectious hepatitis).

Incidence: The causes of hepatomegaly depend on the patient's age, geographical location, and metabolic-nutritional status. Hepatomegaly occurs in countries with hepatitis epidemics, children suffering from malnutrition, food contaminated with chlorinated hydrocarbons, and grains and oils contaminated with Aspergillus fungi. Some 25 percent of adults in the United States are estimated to have metabolic dysfunction-associated steatotic liver disease (MASLD), formerly nonalcoholic fatty liver disease (NAFLD). An enlarged liver is caused primarily by alcoholism in the United States and Europe and by protein malnutrition in infancy and early childhood in some countries. Uncontrolled diabetes and obesity often cause people to have fatty livers.

Symptoms: Hepatomegaly often produces no symptoms, although the liver may be tender to the touch, and the patient may experience some abdominal pain or a feeling of fullness. Asymptomatic cases are usually related to congenital cystic disease, metastasis, or alcoholism. Upon palpitation, an alcoholic liver is enlarged and firm. In alcoholic hepatitis, hepatomegaly may be associated with jaundice, loss of appetite, and vomiting. In alcoholic cirrhosis, the enlarged liver is tender and may be related to hepatitis. It is usually asymptomatic but occasionally presents with abdominal pain, jaundice, gastrointestinal complaints, and ascites. In cardiac cirrhosis, the liver may be slightly enlarged and tender. In nodular cirrhosis, the liver is palpable and firm with a blunt edge.

Hepatomegaly with fever and tenderness may be due to acute viral hepatitis (A and B), mononucleosis, and ascending cholangitis (bile duct infection). In hepatocytic adenomas (in women aged thirty to forty), solitary tumors of up to ten centimeters in diameter in the right lobe are typically present, usually the result of the use of hormones and corticosteroids. Hepatomegaly with gross or occult blood in the stool would suggest metastatic neoplasm of the gastrointestinal tract.

In hepatocellular carcinoma, symptoms may be vague and include loss of appetite and body weight, nausea, weakness, and sometimes fever with chills. If the tumor blocks the bile duct (cholangiocarcinoma), then symptoms may include jaundice, black-colored urine, pale stool, and ascites.

Screening and diagnosis: The procedure for diagnosis depends on the suspected cause of hepatomegaly. The physician conducts a physical examination and takes the patient’s history. Through skillful palpitation, the physician can determine whether the mass or swelling in the liver area is an enlarged liver. Then, the physician can use the symptoms reported by the patient to begin to distinguish between the causes of hepatomegaly.

Liver function tests aid in further diagnosis. The initial workup involves a complete blood count, urinalysis, sedimentation rate study, chemistry panel, amylase and lipase level testing, and an abdominal X-ray followed by ultrasound, computed tomography (CT) scans, and magnetic resonance imaging (MRI).

Additional tests are conducted based on the suspected condition. Patients who are likely to have hepatocellular carcinoma undergo a CT scan of the abdomen, followed by biopsy and histopathology to confirm the diagnosis. A circulation time test and spirometry can confirm the diagnosis if chronic heart failure is suspected. A chest X-ray and electroencephalograph (EEG) are also needed. If obstructive jaundice is suspected, endoscopic retrograde cholangiopancreatography may be done following a CT scan of the abdomen. Antibody titers, blood smears, or skin tests diagnose infectious hepatomegaly-related diseases.

Treatment and therapy: Treatment for chronic enlarged liver depends on the underlying cause and the degree of liver damage, especially in the case of cancer. In nonalcoholic fatty liver cases, where any liver damage is minimal, the patient is directed to lose weight, exercise, and avoid alcohol. In advanced stages of hepatomegaly, the liver may undergo necrosis (due to hepatitis, alcoholism, or drug and toxin exposure) and fibrosis (due to alcoholic cirrhosis, chemical carcinogenesis, or liver cancer). In patients with metastatic tumors, chemotherapy and nuclear medicine may prolong life. The treatments for hepatocellular carcinoma include liver transplant, chemotherapy, and radiation. However, death generally occurs within six to twenty months.

Prognosis, prevention, and outcomes: Hepatomegaly is a symptom of liver diseases and other conditions. The prognosis is good if the underlying condition causing the enlarged liver can be successfully treated. Ways to prevent hepatomegaly include exercising and eating healthfully, avoiding contact with others’ blood and bodily fluids to minimize the risk of hepatitis, limiting contact with toxins, moderating alcohol consumption, avoiding medications like acetaminophen while drinking alcohol, and avoiding drugs and supplement overuse.

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