Not so mass effect? Finding of a remarkable 'incidentaloma' in a teenager with neurofibromatosis.

A 13-year-old boy with neurofibromatosis type 1 presented to the emergency department twice in a fortnight with moderate intermittent abdominal pain, radiating to the back and associated with nausea and vomiting. He examined as a well child with a soft abdomen and minimal tenderness. A history of constipation was identified but he failed to respond to a trial of laxatives. Subsequent ultrasound abdomen demonstrated a large mass surrounding the porta hepatis. MRI further characterised a focal, non-aggressive lesion extending from his liver, encapsulating his pancreas, portal vessels and laterally displacing his spleen and left kidney. Biopsy performed at a specialist cancer treatment hospital of our reference later confirmed this to be a benign neurofibroma of a size not previously reported in the literature. He will be managed conservatively with surveillance imaging and the potential for chemotherapy should the lesion continue to grow. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.