Introduction: Mesenchymal hamartoma of liver (MHL) is the second most common benign liver tumor in children. This tumor typically presents as a large benign cystic mass, solid or mix in children less than three years. Prenatally, it may grow quickly to an abnormal size that may lead to death or hydrops. Prenatal suspicion arises by increasing maternal serum α-FP or HCG and polyhydroamnious and can usually identify the case in the last trimester of pregnancy by ultrasound.
Case presentation: The patient was a sick 19 day old baby boy. The patient was admitted to the hospital due to the poor feeding, restlessness and nausea. On physical examination, a mass was found on the left side of the abdomen. In the MRI of the abdomen, the heterogeneous multi-lobulated mass was reported in the upper quadrant of the abdomen. Incision and drainage was done and purulent material was drained from a large abscess located in the left lobe of the liver. Finally, the pathology report showed that the infected mesengymal hamartoma of the liver.
Conclusion: In neonatal period MHL can lead to emergency surgery due to fluid or puss accumulation in the cysts. Complete surgical removal is the preferred treatment and histopathological diagnosis helps.