Hepatomegaly

Definition and Normal Liver Size

• Yamada's Textbook of Gastroenterology, 7th ed.

Clinical Assessment

Limitations of Physical Examination

• Unusual firmness of the liver edge
• Irregular or nodular surface
• Hepatic tenderness - perhaps the most reliable physical finding; discomfort on palpation or percussion of the right upper quadrant (vs. left) is clinically significant

Associated Physical Findings in Liver Disease

• Harrison's Principles of Internal Medicine, 22nd ed.

Causes of Hepatomegaly

1. Parenchymal Liver Diseases

• Viral hepatitis (acute and chronic - Hepatitis A, B, C, D)
• Alcoholic liver disease - fatty liver, alcoholic hepatitis, cirrhosis
• Non-alcoholic fatty liver disease (MASLD/NAFLD) - often found incidentally; hepatomegaly may be the only physical finding alongside mildly elevated transaminases
• Cirrhosis (marked hepatomegaly typical of advanced cirrhosis)
• Drug-induced liver injury (e.g., antiretrovirals, sulfonamides, chemotherapy)

2. Infiltrative / Storage Disorders

• Hepatic steatosis (fatty infiltration from obesity, insulin resistance, hyperlipidemia)
• Amyloidosis - sinusoidal infiltration causes marked hepatomegaly
• Glycogen storage diseases (GSDs):
  • GSD Type III (Cori disease) - hepatomegaly + ketotic hypoglycemia + elevated AST/ALT and CK
  • GSD Types VI and IX - typically asymptomatic hepatomegaly with elevated transaminases
  • GSD Type 0 (glycogen synthase deficiency) - notably, hepatomegaly does NOT occur
• Gaucher disease, Niemann-Pick disease (lysosomal storage disorders)
• Mucopolysaccharidoses - hepatomegaly is a feature of most types
• Pompe disease (GSD Type II) - cardiac and skeletal muscle + liver involvement

3. Vascular Causes

• Congestive heart failure / right heart failure - hepatomegaly + elevated JVP + peripheral edema + ascites ("congestive hepatopathy")
  • In Fontan circulation patients, hepatomegaly may indicate Fontan obstruction
• Budd-Chiari syndrome - hepatic venous occlusion causing abdominal pain, ascites, and hepatomegaly (classic triad described by Budd and Chiari)
• Sinusoidal obstruction syndrome (veno-occlusive disease) - often post-chemotherapy; non-specific hepatomegaly with patent major hepatic veins on imaging

4. Neoplastic

• Hepatocellular carcinoma (HCC)
• Metastatic liver disease - hepatomegaly indicates advanced disease (e.g., in colorectal, gastric, esophageal, ovarian cancers)
• Lymphoma - hepatic involvement
• Kaposi sarcoma (in HIV/AIDS)

5. Infectious / Inflammatory

• Infectious mononucleosis (EBV)
• CMV hepatitis
• Mycobacterium avium complex (MAC), Mycobacterium tuberculosis (especially in AIDS)
• Enteric fever (typhoid/paratyphoid) - liver biochemistry abnormalities ± hepatomegaly
• Visceral leishmaniasis - massive hepatosplenomegaly
• Amebic liver abscess
• Cryptosporidiosis (biliary involvement)
• Bacillary peliosis hepatis (in AIDS)

6. Biliary/Obstructive

• Cholestatic diseases (primary biliary cholangitis, primary sclerosing cholangitis)
• Extrahepatic biliary obstruction
• Polycystic liver disease (ADPKD) - hepatomegaly from isolated dominant cysts, multiple large cysts, or diffuse polycystic involvement

7. Other / Systemic Diseases

• Sarcoidosis - liver involvement in 20-30%; often asymptomatic with abnormal LFTs; rarely portal hypertension or hepatic insufficiency
• Vitamin A toxicity - hepatomegaly with histological changes + hyperlipidemia
• Anemia (hemolytic disorders may cause hepatosplenomegaly)

Differential Diagnosis in Special Populations

HIV/AIDS patients (Box 35.6, Sleisenger & Fordtran)

• Hepatitis C (most common in HAART era)
• MAC, MTB
• CMV, Cryptococcus, Pneumocystis jiroveci, Microsporidia
• Bacillary peliosis hepatis
• Lymphoma, Kaposi sarcoma
• Drug-induced (antiretrovirals, sulfonamides)
• Biliary: CMV cholangitis, Cryptosporidiosis, Microsporidia

Investigations

Laboratory Tests

• LFTs: ALT, AST, ALP, GGT, bilirubin (direct/indirect), albumin, PT/INR
• CBC: thrombocytopenia - often the first indicator of advanced fibrosis
• Viral hepatitis serology: HBsAg, anti-HCV, anti-HAV, EBV/CMV if indicated
• Metabolic panel: fasting glucose, lipid panel (for MASLD)
• Autoimmune markers: ANA, ASMA, AMA (for autoimmune hepatitis, PBC)
• Iron studies + ferritin: hemochromatosis
• Ceruloplasmin: Wilson's disease in younger patients
• AFP: screening for HCC

Imaging

• Ultrasound (US) - first-line; confirms hepatomegaly, assesses echotexture (fatty liver = diffuse echogenicity, "starry sky" in acute hepatitis), detects focal lesions, assesses vasculature
• CT / MRI - better characterization of focal lesions, vascular anatomy, and staging
• Elastography (transient, acoustic radiation force impulse, MR elastography) - non-invasive assessment of hepatic fibrosis and stiffness
• MR elastography - more sensitive but more expensive

Liver Biopsy

• Diagnosis (when non-invasive tests are insufficient)
• Severity grading (activity of inflammation)
• Stage (degree of fibrosis and cirrhosis)
• Response to treatment

• Harrison's Principles of Internal Medicine, 22nd ed.

Key Points Summary