Paediatric Mesenchymal Hamartoma of Liver-A Diagnostic Dilemma

Introduction and Importance: Benign tumors of the liver are relatively rare in children. Mesenchymal hamartoma (MH) is a benign tumor of the liver. It is the second most common benign pediatric hepatic tumor after infantile hemangioma. Mostly it is seen in children less than 2 years of age. The diagnosis of this tumor is difficult because of nonspecific clinical symptoms and lack of definitive laboratory studies. The precise diagnosis of mesenchymal hamartoma relies on histological evaluation of the tissue.We hereby present a rare case in a 2 year old child with mesenchymal hamartoma and its diagnostic challenges. Case presentation: A 2 year old previously healthy male was referred to our institution for evaluation of a liver mass. He complained of loss of apetite and abdominal distension since last 10 weeks. He had no complaints of fever/trauma. Clinical findings and Investigations: On per abdomen examination,there was a presence of large, non tender hepatomegaly with no shifting dullness present. On radiological evaluation, Ultrasound abdomen showed solitary right lobe mass. On further imaging, CT scan of the abdomen was done which showed a large multiloculated lesion in right lobe liver with arterial enhancing intervening septae within.The lesion was compressing and displacing right portal vein and right hepatic vein. At that time, laboratory evaluation showed normal liver function tests, serum AFP and other blood parameters. Differentials of liver cyst, hydatid cyst and biliary cystadenoma was made. Intervention and outcome: After discussion in multidisciplinary care, he was planned for surgery which would provide the exact histological diagnosis also in such cystic lesion of liver.He was optimized for surgery and subsequently underwent right hepatectomy with resection of the ~14× 12 cm mass. No major periperative complications developed and patient was discharged from hospital on POD6. The pathological review of the resected mass showed mixture of bile ducts, vessels, irregular liver cell plates and loose mesenchyme containing variable sized cysts consistent with a mesenchymal hamartoma. He is asymptomatic at the time of regular follow-up visits. Relevance and Impact: Benign tumors of the liver are relatively rare in children. The diagnosis of mesenchymal hamartoma still remains a challenge with non –specific complaints, normal laboratory findings and delay in diagnosis can lead to complications from local compression. Though advance imaging can diagnose this entity if index of suspicion is high but Differentiating it from other tumors such as an undifferentiated embryonal sarcoma is difficult on imaging alone. Hence surgical excision is the gold standard for diagnosing to reach the final histological diagnosis and treating these entities.