Hepatic regenerating nodules: a mimic of recurrent cancer in children

Background. Pseudometastatic lesions of the liver may be discovered inciden tally in children previously treated for malignant tumour. Objective. To describe the radiological pattern of these lesions and to ana lyse their pathogenesis. Materials and methods. Nine children, 2-12 years' old at the time of diagno sis, are described in this retrospective multicentre report. The primary tu mours were: nephroblastoma (n = 2), neuroblastoma (n = 2), Ewing's tumour/P NET (n = 2), non-Hodgkin's lymphoma (n = 1), and osteosarcoma (n = 2), trea ted by surgery (8/9), chemotherapy (9/9), intensive chemotherapy and bone-m arrow transplantation (5/9), and radiotherapy (7/9). Three children suffere d veno-occlusive disease (VOD) during treatment. The hepatic assessment was performed by sonography (8/9), Doppler (7/9), multiphase spiral CT (8/9) a nd MRI (7/9). Results. Lesions were discovered 15 months to 16 years after completing tre atment. CT was the most sensitive modality for diagnosis. Lesions were mult iple in eight cases, measured 2-50 mm, and appeared hypervascular on the ar terial phase of CT and/or MRI in every case. Metastases were excluded on th e basis of histological verification (n = 2) and clinical and radiological follow-up. Conclusion. Pseudometastatic hypervascular hepatic nodules can appear after treatment of a malignant tumour in children. The hypothesis of benign rege nerative lesions secondary to treatment and/or VOD is considered.