MRI features of plexiform neurofibromas involving the liver and pancreas in children with neurofibromatosis type 1

Aim: To describe magnetic resonance imaging (MRI) findings of plexiform neurofibromas (PNF) involving the liver and pancreas in paediatric patients with neurofibromatosis type 1 (NF1).

Materials and methods: A retrospective search of the hospital database was undertaken to find cases of PNF in the porta hepatis, hilar neurofibroma, and hepatic neurofibroma over a 12 year period. The images were analysed and a review of the charts was undertaken.

Results: Five paediatric patients were identified with extensive PNFs involving the liver. In all cases, the PNFs involved the liver along the intrahepatic portal distribution. Additionally, the gallbladder fossa was affected in 2/5 patients, the pancreatic head in 4/5 patients, the pancreatic neck in 2/5 patients, and the pancreatic tail in 1/5 patients. All tumours showed low signal intensity (SI) on T1-weighted images and high SI with a central target sign on water-sensitive sequences. No patient showed any signs or symptoms, nor required treatment or surgery related to hepatic or pancreatic involvement. Intrahepatic PNFs were stable over a median follow-up time of 3.6 years (range 3 months to 8.8 years).

Conclusions: Intrahepatic and pancreatic involvement, although rare, does occur in paediatric NF1 patients. The MRI findings of the tumour are similar to the PNFs that occur more commonly elsewhere in this population. The hallmark of liver involvement is the periportal distribution.