Long-term follow-up of liver alveolar echinococcosis using echinococcosis multilocularis ultrasound classification

Abstract

BACKGROUND When Echinococcus multilocularis infects humans as a false intermediate host, alveolar echinococcosis (AE) usually manifests primarily intrahepatically and is initially asymptomatic. If the disease remains undiagnosed and untreated, progressive growth occurs, reminiscent of malignant tumours. The only curative therapy is complete resection, which is limited to localised stages, and palliative drug therapy is used otherwise. Consequently, early diagnosis and reliable detection of AE lesions are important. For this reason, abdominal ultrasonography, as the most common primary imaging for AE, relies on classification systems. AIM To investigate how hepatic AE lesion sonomorphology changes over time in the Echinococcosis Multilocularis Ulm Classification (EMUC)-ultrasound (US) classification. METHODS Based on data from Germany’s national echinococcosis database, we evaluated clinical and US imaging data for 59 patients according to the AE case definition in our preliminary retrospective longitudinal study. There had to be at least two liver sonographies ≥ 6 mo apart, ≥ 1 hepatic AE lesion, and complete documentation in all US examinations. The minimum interval between two separately evaluated US examinations was 4 wk. The AE reference lesion was the largest hepatic AE lesion at the time of the first US examination. To classify the sonomorphologic pattern, we used EMUC-US. In addition to classifying the findings of the original US examiner, all reference lesions at each examination time point were assigned EMUC-US patterns in a blinded fashion by two investigators experienced in US diagnosis. Statistical analysis was performed using SAS version 9.4 (SAS Institute Inc., Cary, NC, United Stated). P values < 0.05 were considered statistically significant. RESULTS The preliminary study included 59 patients, 38 (64.5%) women and 21 (35.6%) men. The mean age at initial diagnosis was 59.9 ± 16.9 years. At the time of initial ultrasonography, a hailstorm pattern was present in 42.4% (25/59) of cases, a hemangioma-like pattern in 16.9% (10/59), a pseudocystic pattern in 15.3% (9/59), and a metastasis-like pattern in 25.4% (15/59). For the hailstorm pattern, the average lesion size was 67.4 ± 26.3 mm. The average lesion size was 113.7 ± 40.8 mm with the pseudocystic pattern and 83.5 ± 27.3 mm with the hemangioma-like pattern. An average lesion size of 21.7 ± 11.0 mm was determined for the metastasis-like pattern. Although the sonomorphologic pattern remained unchanged in 84.7% (50/59) of AE reference lesions, 15.3% (9/59) showed a change over time. A change in pattern was seen exclusively for AE lesions initially classified as hemangioma-like or pseudocystic. A total of 70% (7/10) of AE lesions initially classified as hemangioma-like showed a relevant change in pattern over time, and 85.7% (6/7) of these were secondarily classified as having a hailstorm pattern...

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

“…In 2015, Azizi et al correlated MR tomographic AE lesions classified by Kodama with [18F] FDG uptake on PET-CT and demonstrated increased PET activity for type I-III microcysts [29]. Given the potential for AE to change its morphological presentation during the course of disease, the retrospective design of this investigation with sometimes months-long intervals between diagnostic modalities represents a major shortcoming [30]. Our study results support the need to perform a one-time CEUS to exclude fox tapeworm disease in the case of an incidentally first diagnosed echo-rich mass of the liver (suspected typical hemangioma) in high-endemic areas and the concomitant presence of risk factors for AE [31][32][33].…”

Initial Risk Assessment in Patients with Alveolar Echinococcosis—Results from a Retrospective Cohort Study

“…This shift might be attributed to a higher proportion of early-stage AE (stage I or II) in our cohort compared to earlier cohorts [ 8 ]. In contrast to late-stage AE, early lesions allow for curative resection or remain stable with early medical treatment [ 8 , 21 ]. The increased availability and accessibility of imaging techniques at all healthcare levels might explain this change over time.…”

“…The increased availability and accessibility of imaging techniques at all healthcare levels might explain this change over time. Early-stage AE is often an incidental finding, meaning that symptoms such as abdominal discomfort and pain have not yet occurred [ 5 , 8 , 21 ].…”

“…An increasing or decreasing diameter proved to significantly raise or lower the odds for an adverse outcome. Prior research indicated that low PNM stages tended towards a beneficial outcome [ 8 ], and that advanced stages were associated with increased mortality [ 21 ]. Our results confirm that staging according to the PNM classification at first presentation is an important and reliable tool to predict the clinical course of disease, especially ‘N’, the involvement of neighbouring organs.…”

18F-FDG-PET/MR in Alveolar Echinococcosis: Multiparametric Imaging in a Real-World Setting

“…The value of (contrast-enhanced) ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI) has been demonstrated extensively for disease distribution and description of AE lesions [ 12 , 13 , 14 , 15 , 16 , 17 , 18 ]. Especially the excellent tissue contrast in MRI enables detailed lesion characterization and led to the development of a classification system based on morphological features, first described by Kodama et al [ 19 ].…”