Introduction: Primitive liver tumors represent 0.3-2% of all pediatric tumors, of which malignancies account for approximately 75%. Benign liver neoplasms include, though rare, focal nodular hyperplasia (FNH) and nodular regenerative hyperplasia (NRH). In recent years, a growing number of cases of FNH and NRH have been incidentally diagnosed during the follow-up of patients undergoing chemotherapy and/or radiotherapy for non-hepatic primitive tumors, representing a differential diagnosis with metastatic relapse of the primitive disease. Methods: Our paper represent a retrospective review of children 16< years of age with diagnosis of NRH and FNH performed at our Department (Radiology Unit- Santobono Pausllipon), discovered during routine examination. Results: 12 patients had a diagnosis of FNH and NRH. in 10 (83%) patients were diagnosed with FNH, while in 2 (17%) of NRH. In 11 cases (91%) imaging was concluded. In only one case (9%) it was necessary to perform biopsy in order to diagnose FNH. Conclusion: In our experience, according to reports in the literature to date, CT and MRI were the most appropriate imaging techniques for the characterization of these liver lesions. A regular follow-up with US and MRI is recommended to monitor the evolution of liver diseases.
