Congenital myofibromatosis of the porta hepatis: a case report

Infantile myofibromatosis (IM) of the hepatic hilum is an extremely rare condition. Although IM is expected to undergo spontaneous tumor regression, surgical management of hilar IM presenting with obstructive jaundice can be challenging. A male infant was born at 38 weeks of gestation with a birth weight of 2628 g. A tumor in the porta hepatis had been detected prenatally at 32 weeks of gestation. Postnatal MRI and contrast-enhanced CT revealed a large hilar mass extending into the right hepatic lobe, encasing the hepatic artery, portal vein, and common bile duct, with marked bile duct stenosis. At 19 days of age, the patient developed cholangitis, hepatic dysfunction, and worsening jaundice. Following antibiotic treatment, an open biopsy and hepatic duct drainage were performed on day 26 under intraoperative ultrasound guidance, with a tube placed in the bile duct. Bile was reinfused into the gastrointestinal tract via a nasoduodenal tube. Pathological examination showed minimal cellular proliferation, raising suspicion for IM or infantile fibrosarcoma. Genetic testing confirmed IM by detecting a PDGFRB tandem duplication. While awaiting spontaneous tumor regression, complications such as drain dislodgement and infection necessitated repeated interventions. Therefore, on day 241, a side-to-side hepaticojejunostomy was performed without tumor resection. Two years postoperatively, the child remains well without major complications, and imaging shows significant tumor regression. Temporary external biliary drainage followed by bilio-enteric reconstruction should be considered in infants who have myofibromatosis of the hepatic hilum causing cholestasis.