Evaluation of Diagnostic Criteria for Liver Metastases of Adenocarcinomas and Neuroendocrine Tumours at Conventional Ultrasound, Unenhanced Power Doppler Sonography and Echo-Enhanced Ultrasound

PURPOSE: In order to improve the differential diagnosis between liver metastases of neuroendocrine tumours and adenocarcinomas, criteria for the masses at conventional ultrasound, unenhanced power Doppler sonography and echo-enhanced ultrasound were evaluated. METHODS: Seventy-three patients with histologically proven liver metastases of a neuroendocrine tumour (n = 26) or an adenocarcinoma (n = 47) were investigated by conventional ultrasound as well as unenhanced power Doppler sonography and echo-enhanced ultrasound focusing on specific properties of the lesions. RESULTS: Liver metastases of neuroendocrine tumours and adenocarcinomas showed a different contrast behaviour with echo-enhanced sonography. A hypervascularisation at the arterial and capillary phase were found in 85% of the neuroendocrine metastases, and in 17% of the masses of adenocarcinomas, respectively (p < 0.05). CONCLUSIONS: The successful treatment of liver metastases requires a highly sensitive and specific diagnostic procedure for their differentiation. A hypervascularisation of the lesions during the arterial and capillary phase at echo-enhanced ultrasound may point to a neuroendocrine primary tumour. However, histology is the only standard of reference for the differentiation of liver metastases, and is necessary for optimal therapy.