Screening Sonography Detection of Liver Masses: Assessing the Non-emergent Nature of Focal Nodular Hyperplasia

The Basic Emergency Service (BES) in Portugal operates in peripheral healthcare units with limited technological resources, where the main goal is rapid patient triage and timely referral whenever necessary. In units located far from a reference hospital, screening ultrasound may support clinical decision-making during the initial assessment. However, with its increasing use, incidental detection of abnormalities unrelated to the presenting complaint has also become more frequent, including focal liver lesions. We report the case of a 28-year-old woman presenting to a BES with abdominal complaints, in whom a screening ultrasound identified a hepatic mass that was ultimately considered unrelated to the symptoms motivating the emergency visit. Although the lesion raised diagnostic interest, the sonographic findings did not suggest an immediately life-threatening hepatic condition, and the overall clinical context did not justify emergent transfer to the reference hospital solely because of this incidental finding. The patient was therefore managed according to the acute complaint and referred for outpatient imaging characterization. Dedicated liver imaging later showed features most consistent with focal nodular hyperplasia, which remained a probable radiologic diagnosis in the absence of histologic confirmation. This case emphasizes an important challenge in peripheral emergency settings: sonographers performing screening ultrasound should be able to recognize findings that require urgent hospital referral and distinguish them from lesions that may be safely investigated in an ambulatory setting without compromising patient safety. The role of screening ultrasound in this context is not to establish a definitive pathological diagnosis, but rather to support clinical orientation, reduce unnecessary alarms, avoid inappropriate emergency referrals, and contribute to more efficient use of healthcare resources.