Focal Nodular Hyperplasia (FNH)/FNH-Like Lesions: An Important Potential Mimic of Relapsed Malignancy in Pediatric Cancer Patients.

Focal nodular hyperplasia (FNH) is a rare benign lesion of the liver, which is becoming increasingly recognized in survivors of pediatric cancer. These lesions are under-reported, but do not require further investigation or treatment. We present two cases with unusual imaging findings consistent with an FNH/FNH-like process after completing intensive cancer treatment; both patients were managed without invasive investigation or treatment and remain clinically well. It is important to recognize FNH/FNH-like lesions in this cohort of patients and avoid unnecessary invasive investigation and management.