A Malignant Hepatoblastoma Mimicking a Benign Mesenchymal Hamartoma: Lessons Learned.

Differentiating hepatoblastomas from other congenital benign hepatic tumors is key to surgical management. We, herein, present an unusual case of an antenatally diagnosed liver lesion assessed in the neonatal period. Because of its predominantly cystic ultrasound/MRI appearance and borderline alpha-fetoprotein serum levels the diagnosis of mesenchymal hamartoma was favored and protocol-based tumor resection was performed. Due to the intraoperative diagnosis of a fetal subtype of hepatoblastoma with positive resection margins the child had to undergo a second laparotomy. This report raises awareness to an unusual appearance of hepatoblastoma and discusses noninvasive imaging clues to consider atypical appearances of hepatoblastoma preoperatively as they can have profound implications in patient management.