Published online May 15, 2019. doi: 10.4251/wjgo.v11.i5.436
Peer-review started: January 30, 2019
First decision: March 14, 2019
Revised: March 19, 2019
Accepted: March 26, 2019
Article in press: March 26, 2019
Published online: May 15, 2019
Hepatic neuroendocrine neoplasm (hNEN) is a highly heterogeneous tumor. The exact identification of the source and malignant degree of hNEN is important. However, there is a lack of information regarding diagnosis of hNEN with imaging. In addition, no studies have compared the imaging between hNEN and hepatocellular carcinoma (HCC) and among different sources and malignant degrees of hNEN.
To compare the ultrasound characteristics between hNEN and HCC and among different sources and malignant degrees of hNEN.
A total of 55 patients with hNEN were recruited and defined as the hNEN group. Among them, 35 cases of hNET were defined as the hNET group. Twenty cases of hepatic neuroendocrine carcinoma (hNEC) were defined as the hNEC group. Among the 55 lesions, 29 were transferred from the pancreas, 20 were from the gastrointestinal tract, and six were from other sites. In total, 55 patients with HCC were recruited and defined as the HCC group. The characteristic differences of B-mode ultrasound and contrast-enhanced ultrasound (CEUS) between hNEN and HCC and among different sources and malignant degrees of hNEN were compared.
In the hNEN group, the proportions of multiple liver lesions, unclear borders, and high echo lesions were higher than those in the HCC group. The proportions of non-uniform echo and peripheral acoustic halo were lower than those in the HCC group (P < 0.05). The washout to iso-enhancement time and washout to hypo-enhancement time were lower than those in the HCC group (P < 0.05). The characteristics of B-ultrasound and CEUS among different sources of hNEN were similar, and the differences were not statistically significant (P > 0.05). B-mode ultrasound characteristics of hNET and hNEC were similar. The proportions of low enhancement at portal venous phase, non-uniform enhancement forms, and combined tumor vasculature in the hNEC group were larger than those in the hNEN group (P < 0.05).
Compared with HCC, hNEN showed multiple intrahepatic lesions, uniform high echo, uniform high enhancement at arterial phase, and rapid washout. Low enhancement at portal venous phase, overall non-uniform enhancement form, and the proportion of combined tumor vasculature in hNEC were larger than those in hNET.
Core tip: Clinically, hepatic neuroendocrine neoplasm (hNEN) is rare, and few reports are currently available on the imaging diagnosis of hNENs. In this study, by comparing hNEN and hepatocellular carcinoma, hNEN from different sources, and differentiation, it was found that the ultrasound characteristics of hNEN are mostly multiple, uniform hyperechoic masses. The enhancement at the arterial phase was mostly uniform and high, and the washout was rapid compared with hepatocellular carcinoma. Compared with hepatic neuroendocrine tumor, the enhancement at the portal venous phase of hepatic neuroendocrine carcinoma was low, and the enhancement form was non-uniform.