Differentiation of hepatic alveolar echinococcosis with a hemangioma-like pattern compared to typical liver hemangioma using contrast-enhanced ultrasound: a pilot study

Pictorial review of hepatic echinococcosis: Ultrasound imaging and differential diagnosis

Echinococcosis is a zoonotic disease caused by parasites belonging to the genus Echinococcus that primarily affect the liver. The western plateau and pastoral areas of China are high-risk regions for hepatic cystic echinococcosis and hepatic alveolar echinococcosis (HAE). The high late mortality rate associated with HAE underscores the critical need for early diagnosis to improve cure rates and mitigate the disease burden in endemic areas. Currently, the World Health Organization recommends ultrasonography as the preferred initial screening method for hepatic echinococcosis. However, distinguishing between specific types of lesions, such as those of hepatic cystic echinococcosis and HAE, and other focal liver lesions is challenging. To address this issue, contrast-enhanced ultrasound is recommended as a tool to differentiate solid and cysto-solid hepatic echinococcosis from other focal liver lesions, significantly enhancing diagnostic accuracy. In this comprehensive review, we discuss the progression of hepatic echinococcosis and detail the imaging features of various types of echinococcosis using conventional, contrast-enhanced, and intraoperative ultrasound techniques. Our objective is to provide robust imaging evidence and guidance for early diagnosis, clinical decision making, and postoperative follow-up in regions with high disease prevalence.

Computed tomography angiography of liver alveococcosis: a case report

BACKGROUND

Alveococcosis, helminthiasis caused by the larvae of Alveococcus multilocularis, is characterized by the formation of parasitic nodes in the liver. This clinical case is a rare occurrence of liver alveococcosis in Uzbekistan.

CASE PRESENTATION

We present a case of a 33-year-old Asian woman from Uzbekistan who complained of discomfort in the epigastric region and right hypochondrium, along with general weakness. She had been experiencing symptoms for 5 months when a routine ultrasound examination revealed a structural formation in the liver. Patient was investigated by using contrast enhanced computed tomography (CT) and diagnosed with liver alveococcosis with multiple lesions. Patient underwent diagnostic laparotomy with obtaining gross specimen, biomaterial was examined microscopically and found that there were small fragments of fibrous tissue determined together with small groups of cystic formations and walls consisted of chitin. Moreover, contrast enhanced CT allowed us to differentiate liver alveococcosis from cavernous hemangioma, hepatocellular carcinoma, and liver metastases from unknown source.

CONCLUSION

Contrast enhanced CT plays a major role in differentially diagnosing liver alveococcosis and makes it the first line method of choice for the consideration of the future treatment and surgical interventions.

Can contrast-enhanced ultrasound differentiate the type of hepatic echinococcosis: cystic echinococcosis or alveolar echinococcosis?

BACKGROUND

Hepatic echinococcosis (HE) is a zoonotic disease caused by Echinococcus, and Echinococcus granulosus and E. multilocularis are the most common, causing cystic echinococcosis (CE) and alveolar echinococcosis (AE), respectively. Contrast-enhanced ultrasound (CEUS) is an imaging technique which has been recommended for identifying focal lesions in the liver. However, the effect of CEUS on the differentiation of hepatic echinococcosis type remains unclear.

METHODS

Twenty-five patients with 46 HE lesions confirmed by histopathology in our hospital from December 2019 to May 2022 were reviewed by conventional ultrasound (US) and CEUS examinations, respectively. After US was completed, the CEUS study was performed. A bolus injection of 1.0-1.2 ml of a sulfur hexafluoride-filled microbubble contrast agent (SonoVue^®) was administered. The images and clips of the lesions by US and CEUS were reviewed retrospectively. The lesions detected using US were evaluated including the location, size, morphology, margin, internal echogenicity and the internal Doppler signal. The lesions detected using CEUS were evaluated including the enhancement degree, enhancement pattern and enhancing boundary in different phases. The diagnoses of lesions by US or CEUS were respectively recorded. By taking the histopathology as the gold standard, the paired Chi-square test was performed with statistical software (IBM SPSS; IBM Corp., Armonk, NY, USA), and the results of differentiation of HE type by US and CEUS were statistically analyzed.

RESULTS

A total of 46 lesions were involved in 25 patients, including 10 males (40.0%) and 15 females (60.0%) aged 15-55 (42.9 ± 10.3) years. By histopathology, 24 lesions of nine patients were diagnosed as CE and 22 lesions of 16 patients were diagnosed as AE. Among the 46 HE lesions, compared with histopathological examination, the accuracy rate was 65.2% and 91.3% in US and CEUS findings, respectively. Among the 24 CE lesions, 13 lesions were correctly differentiated by US, and 23 by CEUS. The difference between US and CEUS was statistically significant (Chi-square test, [Formula: see text] = 8.10, df = 23, P < 0.005). Among the total 46 HE lesions, 30 lesions were correctly differentiated by US, and 42 by CEUS. The difference between US and CEUS was statistically significant (Chi-square test, [Formula: see text] = 10.08, df = 45, P < 0.005).

CONCLUSIONS

CEUS is a more effective technique than US for differentiating the type of HE between CE and AE. It could be a reliable tool in the differentiation of HE.

[Diagnostic delaying factors in hepatic alveolar echinococcosis]

PURPOSE

The purpose of this study was to analyze the diagnostic workflow of patients with alveolar echinococcosis (AE) and to identify possible diagnosis-delaying factors.

METHODS

The number and type of diagnostic procedures of patients diagnosed with alveolar echinococcosis were investigated. The disease history was recorded on the basis of questionnaires, the available findings, and data supplements from the hospital information system (SAP). Statistical analyses were performed using SAS version 9.4 and Microsoft Excel version 16.43. The study population of the cross-sectional study included n = 109 patients with confirmed alveolar echinococcosis.

RESULTS

The definitive diagnosis of alveolar echinococcosis of the liver was made at 26.5 ± 65.0 (mean ± standard deviation) months (min - max: 0 - 344, median = 3). The majority of patients were diagnosed because of incidental imaging findings of the liver (n = 74/109 (67.9%)). A total of n = 56/74 (75.7%) of all incidental findings were diagnosed in an outpatient setting, while n = 15/74 (20.3%) of cases were diagnosed during inpatient hospitalization. On average, 1.1 ± 1.2 (0-11, median = 1) ionizing imaging modalities were used for each patient. Contrast-enhanced sonography was received by 0.3 ± 0.5 (0-2, median = 0) patients. Almost all patients (n = 104/109 (95.4%) had at least one suspected hepatic or extrahepatic malignancy at some time. Exclusion of suspected malignancy occurred at a mean of 4.1 ± 16.5 months (0 -133.8, median = 1).

CONCLUSIONS

The diagnostic clarification process of AE patients is lengthy and stressful. The psychological burden of a questionable malignant diagnosis is considerable. Early use of contrast-enhanced sonography and, if necessary, puncture of unclear hepatic masses helps to shorten the difficult diagnostic process.