Imaging appearance of primary hepatic neuroendocrine carcinomas

Objective To investigate the CT and MRI findings of primary hepatic neuroendocrine carcinomas.Methods Imaging findings of 6 patients with pathologically confirmed hepatic neuroendocrine carcinomas were retrospectively analyzed.Four patients underwent plain CT and contrast enhanced CT examinations.The other 2 patients underwent plain MRI and contrast enhanced MRI.Results One out of the 6 cases manifested multicentric tumor which appeared as one large tumor surrounded with multiple small nodules peripherally,and the tumors of the other 5 cases were solitary.On plain CT images,all lesions were well-defined and hypoattenuating with central areas of even lower density except punctuate calcifications at tumor periphery in 1 case.On pre-contrast MRI,the cases manifested heterogeneous low signal intensity on T1 wI and slightly high intensity on T2 WI.On dynamic contrast enhanced CT and MRI,Tumors manifested slight to mild enhancement in arterial phase,slight enhancement in portal venous phase or delayed phase with no enhancement in the center,accompanied by dislocation of surrounding vessels.There Was no lymphadenopathy in peritoneal cavity and retroperitoniurm. Conclusion CT and MRI scanning can demonstrate specific features of primary hepatic neuroendocrine carcinoma,which may help the diagnosis and differential diagnosis of the tumor. Key words: Liver neoplasms;  Carcinoma,neuroendoerine; Tomography,X-ray computed; Magnetic resonance imaging