CT scan demonstrating hepatomegaly.
https://en.wikipedia.org/wiki/Hepatomegaly
Definition
Hepatomegaly is defied as a liver edge 3.5 cm below the right costal margin in newborns and 2 cm below the RCM in older children. The average liver span is 4-5 cm in newborns and 6-8 cm in children at 12 years of age. The border of the liver can be found by palpation, percussion, and auscultation. Of note, the liver may be displaced downward by the diaphragm or thoracic contents leading to false impression of hepatomegaly.
Pathogenesis and Differential Diagnosis
1. Inflammation/Infection-
a. Infectious hepatitis (viruses, bacteria, fungi, parasites)
b. Autoimmune hepatitis
c. Medication associated hepatotoxicity
2. Storage- Inappropriate build up of metagolic components in the liver
a. Glycogen storage diseases
b. Disorders of lipid storage
c. Metals (iron and copper)
d. Tyrosinemia
e. Gaucher's disease
3. Infiltration- Physical space occupied by malignant cells -
a. Primary hepatic tumors
b. Infiltration of leukemic or lymphoma cells.
4. Congestion- "back up" of blood into the liver
a. Congestive heart failure
b. Restrictive pericarditis
c. Budd Chiari
5. Obstruction of Biliary System- "back up" of bile and associated cytotoxic components into the liver
a. Biliary atresia
b. Choledochal cysts
c. Gallstones
Work-Up
The evaluation of the pediatric patient with hepatomegaly should be performed in an orderly fashion based on the age of the patient, history, physical findings, laboratory evaluation, and possible radiographic studies.
1. History
a. Jaundice- hemolysis, bile duct abnormalities, liver inflammation.
b. Family History of liver disease
c. Family history of metabolic disease, neurodegenerative disease,
d. Weight gain and growth- will be poor with severe liver dysfunction
e. Developmental- delay may indicate CNS storage disease
f. Maternal infections during the pregnancy (TORCH)
g. Umbilical catheter use in the newborn period
h. Risk factors for hepatitis A, B, C, D, and E
i. Acholic stools and dark urine- biliary obstruction
j. Drug exposure
k. Symptoms of inflammatory bowel disease
l. Gastrointestinal bleeding
m. Age of onset- early suggest congenital infection or metabolic disorder
2. Physical Findings
a. Fever- systemic disease or infection
b. jaundice
c. Splenomegaly- portal hypertension, infiltration by malignancies and storage diseases, hemolytic disease, hemoglobinopathies
d. Increase of lymph nodes- infection or neoplasia
e. Eye- cataracts. Keyser Fleischer rings, chorioretinitis
f. Developmental delay and neurologic deterioration- characteristic of storage diseases and Wilson’s disease
g. Hemangiomas and bruits
h. Dysmorphic features ? mucopolysaccharidoses
i. Edema- increased venous pressure and hypoalbuminemia
j. Ascites
3. Laboratory Evaluation- initial evaluation should be directed by the clinical presentation, past history, physical findings, and family history.
a. CBC and diff, platelet count, reticulocyte counts, and smear
b. UA
c. Aminopeptidases- indication of liver cell destruction. Alanine aminotranasferase is more specific than aspartate aminotransferase for liver pathology
d. PT, PTT and Albumin are markers for liver synthetic function
e. Bilirubin- evidence of obstruction, cell damage, and hemolysis
f. Alkaline phosphatase and gamma glutamyl transpeptidase indicate biliary obstruction
g. Serum glucose
h. Viral studies for Hepatitis A, B, and C
4. Imaging
a. Ultrasound- define size, consistency, small masses, and blood flow
b. CT and MRI
5. Biopsy
a. May demonstrate parenchymal changes, presence of storage materials, and tissue for enzyme identification.
References
- Wolf Ann, and Lavine Joel Hepatomegaly in Neonates and Children. Pediatrics in Review. Vol. 21 No. 9 September 2000
- Agata Ian and Balisteri William. Evaluation of Liver Disease in the Pediatric Patient Pediatrics in Review. November 1999
- Clemente, Maria Grazia, and Kathleen Schwarz. Hepatitis: General Principles. Pediatrics in Review 32.8 (2011): 333-340.
- Fishbein, Mark, et al. Undetected hepatomegaly in obese children by primary care physicians: a pitfall in the diagnosis of pediatric nonalcoholic fatty liver disease. Clinical pediatrics 44.2 (2005): 135-141.