Mesenchymal hamartoma of the liver demonstrating peripheral calcification in a 12-year-old boy.

Mesenchymal hamartoma of the liver is a rare benign hepatic tumor that typically presents in the first 2 years of life. Approximately 85% of affected children present before the age of 3 years and less than 5% present after the age of 5 years. Although spontaneous regression has been reported in this benign tumor, most mesenchymal hamartomas gradually increase in size and can reach enormous proportions. We present an atypical case of mesenchymal hamartoma in a 12-year-old boy. The boy's age and presence of calcifications on CT demonstrate a unique presentation of this rare entity.