Published online Aug 7, 2020. doi: 10.3748/wjg.v26.i29.4302
Peer-review started: April 3, 2020
First decision: May 26, 2020
Revised: June 9, 2020
Accepted: July 23, 2020
Article in press: July 23, 2020
Published online: August 7, 2020
Human alveolar echinococcosis (AE) is a zoonosis caused by the larval stage of the fox tapeworm echinococcus multilocularis. Untreated, the disease is fatal. The main endemic areas of alveolar echinococcosis (AE) are in Central Europe and Western China.
Early diagnosis is of crucial importance. Imaging techniques play the greatest role here. International comparative studies on imaging are not yet available.
Aim of this study was to evaluate the vascular/biliary involvement of hepatic alveolar echinococcosis and the extrahepatic disease manifestations in a collective of German, French, and Chinese cases.
Consecutively, five experienced examiners evaluated contrast-enhanced abdominal computed tomography (CT) scans for 200 patients with hepatic AE of each of four locations (n = 50) in Germany, France and China according to the echinococcosis multilocularis Ulm classification for CT (EMUC-CT). Vascular/biliary involvement of the hepatic disease as well as the presence of distant extrahepatic manifestations were correlated with the EMUC-CT types of liver lesion.
Distant extrahepatic AE manifestations were significantly more frequent in China than in Europe (P = 0.0091). A significant relationship was found between the presence of distant extrahepatic disease and AE liver lesion size (P = 0.0075). Vascular/biliary structures were involved by the liver lesions significantly more frequently in China than in Europe (P < 0.0001), and vascular/biliary involvement depended on lesion size. Different morphological types of AE liver lesions led to varying frequencies of vascular/biliary involvement and were associated with different frequencies of distant extrahepatic manifestations. Type IV differed significantly in these associations from types I, II, and III (P < 0.0001). With respect to extrahepatic disease, the primary morphology types IV and V of liver lesions were not associated with any case of distant extrahepatic disease. In contrast, distant extrahepatic manifestations in types I–III were found to varying degrees, with a maximum of 22% for type III.
Different CT morphological patterns of hepatic AE lesions influence vascular/biliary involvement and the occurrence of distant extrahepatic manifestations. There are intercontinental differences regarding the characteristics of AE manifestation.
The results may give indications about the behavior of this disease in the context of initial manifestation and progression. A morphological classification of AE liver lesions seems therefore not only useful in order to facilitate the initial differential diagnosis but also indicates a direct clinical impact.