Mesenchymal hamartoma of the liver (MHL) is an uncommon benign tumor found 
primarily in children younger than 2 years of age. We report a rare case of MHL 
with a daughter nodule and atypical histological findings in a 14-month-old 
girl. On admission, computed tomography, magnetic resonance imaging, and 
angiography showed a solid hypovascular mass with a central cystic area in the 
liver. Laparotomy revealed a tumor, 8 cm in size, occupying segment 5 and parts 
of segments 4 and 6 of the liver, and a small nodule, 10 mm in size, in segment 
7. Thus, we performed a partial hepatic resection (S4-6) and tumor extirpation 
(S7). The histological findings of both tumors were the same, but atypical of 
MHL. Recent studies on the pathogenesis of this tumor have found neoplastic 
features such as genetic anomalies and malignant transformation. These findings 
suggest that the conventional approach of completely resecting the tumor 
whenever possible is the best treatment.