Imaging characteristics of hepatic epithelioid hemangioendothelioma

Abstract

Objective To summarize the imaging characteristics of the hepatic epithelioid hemangioendothelioma (EHE). Methods The clinical data of 6 patients with hepatic EHE who were admitted to the Yantaishan Hospital (3 patients), Zhangzhou Hospital of Traditional Chinese Medicine (2 patients) and Zhangqiu Hospital of Traditional Chinese Medicine (1 patient) between March 2007 and June 2014 were retrospectively analyzed. All the patients underwent plain scan and dynamic enhanced scan of computed tomography (CT), and the number, shape, size, location, density or signal, level and method of enhancement of the lesions were observed and analyzed. Six patients were followed up by outpatient imaging examination up to June 2014, and the changes of lesions were observed. Results Among the 6 patients, 1 solitary lesion and 5 multiple lesions were detected, and the total lesions were 125 including 1 patient with 75 lesions. The lesions were round or round-like and originated commonly from the right lobe of liver and hepatic subcapsular with a maximum diameter of 0.5-3.5 cm. Plain scan of CT showed that the lesions in 6 patients had low density with the clear boundary. MRI showed that low T1WI signal and high or slightly high T2WI signal of the lesions were detected in 4 patients. Two patients had liver capsular retraction sign. The ring-like enhancement of 1 lesion and homogeneous enhancement of 5 lesions were found by dynamic enhanced scan of CT in 6 patients and enhanced scan of MRI in 4 patients. Enhanced signal in all the lesions was detected in the delayed phase. Veins into or through lesions were found in 3 lesions, with normal or narrowing vascular cavity. One patient had visible lollipop sign. Of the 6 patients, 5 were confirmed as with metastatic carcinoma of liver, and 1 was suggested as with cholangiocarcinoma. Six patients were diagnosed with hepatic EHE by pathological examination using hepatic biopsy technique. Among the 2 patients with hepatic EHE who didn't receive antineoplastic treatment after the diagnosis, 1 patient received CT examination at year 2 after first visit, which showed capsular retraction sign, and then was diagnosed as with secondary hepatic cirrhosis by MRI at 4 years after first visit. Another patient was diagnosed as with hepatic cirrhosis by CT examination at year 6.5 after first visit. One patient was diagnosed with tumor recurrence of hepatic left lobe by CT reexamination at postoperative year 4, and underwent ultrasound-guided radio frequency ablation (RFA) treatment based on no enlargement of tumor during 1-year follow-up, and then returned a normal condition after half year follow-up. Other 3 patients undergoing operation were followed up at postoperative year 1 , 4, 5 with no recurrence and metastasis. Conclusions Intrahepatic single or multiple nodules and delayed reinforcement by dynamic enhanced scan of CT and MRI are the typical imaging performances of hepatic EHE. There are certain characteristics in the liver the lollipop sign, capsular retraction sign and veins into or through the lesions. Mutual fusion and fibrosis of lesions leading ultimately to secondary liver cirrhosis may be characteristics of EHE growth. Key words: Liver neoplasms; Epithelioid hemangioendothelioma; Tomography, X-ray computed; Magnetic resonance imaging