Hepatic regenerating nodules: a mimic of recurrent cancer in children.
BACKGROUND: Pseudometastatic lesions of the liver may be discovered incidentally in children previously treated for malignant tumour. OBJECTIVE: To describe the radiological pattern of these lesions and to analyse their pathogenesis. MATERIALS AND METHODS: Nine children, 2-12 years' old at the time of diagnosis, are described in this retrospective multicentre report. The primary tumours were: nephroblastoma (n = 2), neuroblastoma (n = 2), Ewing's tumour/PNET (n = 2), non-Hodgkin's lymphoma (n = 1), and osteosarcoma (n = 2), treated by surgery (8/9), chemotherapy (9/9), intensive chemotherapy and bone-marrow transplantation (5/9), and radiotherapy (7/9). Three children suffered veno-occlusive disease (VOD) during treatment. The hepatic assessment was performed by sonography (8/9), Doppler (7/9), multiphase spiral CT (8/9) and MRI (7/9). RESULTS: Lesions were discovered 15 months to 16 years after completing treatment. CT was the most sensitive modality for diagnosis. Lesions were multiple in eight cases, measured 2-50 mm, and appeared hypervascular on the arterial phase of CT and/or MRI in every case. Metastases were excluded on the 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 regenerative lesions secondary to treatment and/or VOD is considered.