Hepatic mesenchymal hamartoma in a preterm newborn: demonstration by low-dose multidetector CT.

Primary liver tumours are very rare in the neonatal period. Differential diagnoses include haemangioendothelioma, malignant hepatoblastoma and mesenchymal hamartoma. Due to non-specific clinical symptoms and indecisive imaging findings, correct diagnosis may be difficult to establish. We report a female preterm newborn who was delivered at 33 weeks of gestation and in whom ultrasonography (US) revealed a large cystic intraabdominal tumour of unknown origin. For further evaluation, contrast-enhanced multidetector computed tomography (CT) was performed on the 4th day of life using a low-dose protocol (80 kVp, 50 mAs, collimation 0.75 mm, total effective dose 3.6 mSv). Based on CT findings, diagnosis of an intrahepatic mesenchymal hamartoma was made and confirmed by tumour resection and histopathological examination. In conclusion, multidetector CT (MDCT) using a low-dose protocol can be exceptionally used to establish diagnosis of a mesenchymal hamartoma in a preterm newborn.