Isolated Gamma-Glutamyl Transferase Elevation in an Asymptomatic Adolescent: An Unusual Presentation of Focal Nodular Hyperplasia.

Incidental liver lesions (ILLs) in children are increasingly being identified due to the widespread use of imaging techniques. Focal nodular hyperplasia (FNH) is relatively rare in pediatric age, typically diagnosed based on characteristic imaging findings. We report the case of a 16-year-old asymptomatic female patient with persistent isolated elevation of gamma-glutamyl transferase (GGT), identified during routine evaluation. Further imaging, including abdominal ultrasound and magnetic resonance imaging with hepatocyte-specific contrast agent, revealed an ILL consistent with FNH, despite the absence of a classical central scar. The adolescent remained asymptomatic, and conservative follow-up was decided. This case highlights the diagnostic relevance of isolated GGT elevation as a potential indicator of FNH.