RESUMO
Mesenchymal Hamartoma (MH) of the liver constitutes the third or the fourth most common tumour of the liver in childhood and occurs most commonly in the first two years of life. It is often misdiagnosed clinically as a malignant tumour because of its rapid increase in size within a short period of time, or as a hepatic collections or abscess because of its cystic appearance. Although a benign lesion, MH may cause heart failure due to arteriovenous shunts, or death as a result of respiratory complications. A typical case of MH was recently encountered in a 6-years-old-boy. The patient presented with progres sive abdominal distension; surgery revealed a large mass arising from the right lobe of the liver. The mass was predominantly formed by fluid collections. Loose mesenchymal tissue and branched, tortuous bile ducts were the key diagnostic features. When predominantly cystic, MH may mimic lymphangioma both grossly and microscopically. Prudent examination of the cystic structures can establish a correct diagnosis.