Neonatal hepatomegaly: in ddx is SLE, neonatal

During the first 2 years of life, the liver is relatively large in relation to overall body size. Determination of normal liver size has been based on age-related clinical indices, including length of the liver edge below the costal margin, span of the liver, and length of the vertical axis of the liver as measured from imaging techniques. The lower edge of the liver normally is palpable up to 2 cm below the right costal margin and to the right of the midline. A liver edge greater than 3.5 cm below the costal margin is considered an indication of hepatic enlargement in the newborn.

Because of variations in the position of the lower margin of the liver caused by alterations in respiratory function, determination of liver span by percussion may be a more reliable indicator of liver size.

Females > 12 y/o: 0.027 x wt lbs + 0.22 x ht inches - 10.75
Males > 12 y/o: 0.032 x wt lbs + 0.18 x ht inches -  7.86

Some authorities consider a liver span greater than 7 cm to be an indication for further evaluation. Based on these guidelines, the infant in the vignette has a normal-size liver and only requires a routine health supervision visit at 1 year of age.

Consultation with a gastroenterologist, hepatic ultrasonography, laboratory testing for hepatitis, and repeat examination in 2 weeks would be appropriate for a child identified as having hepatomegaly, the most common cause of an enlarged liver. Hepatomegaly can result from an infectious process, cirrhosis, storage of glycogen and fat from fatty infiltration or metabolic disease, congestive heart failure, extramedullary hematopoiesis, and hepatic cysts.

Liver tumors also produce hepatic enlargement in infants. Primary liver tumors are the third most common solid abdominal neoplasm in childhood and account for approximately 15% of abdominal masses in children.
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Naveh Y, Berant M. Assessment of liver size in normal infants and children. J Pediatr Gastroenterol Nutr. 1984;3:346-348
Reiff MI, Osborn LM. Clinical estimation of liver size in newborn infants. Pediatrics. 1983;71:46-48