CASE 15667 Published on 04.05.2018

Hepatic fascioliasis

Section

Abdominal imaging

Case Type

Clinical Cases

Authors

António Caetano, Marta Costa, Ana Luísa Proença, Vasco Magalhães Ramalho

Hospital Curry Cabral, Centro Hospitalar Lisboa Central
Rua Antonio Pedro Num 16 RC Esq
1150-046 Lisbon, Portugal
Email:aprocaetano@gmail.com
Patient

74 years, female

Categories
Area of Interest Abdomen ; Imaging Technique CT, Ultrasound
Clinical History
A 74-year-old female patient, natural from Cape Verde, with history of diabetes mellitus and hypertension, presents to the emergency department with fever, anorexia, fatigue and non-productive cough with 4 weeks duration. She had lost 10 kilograms since the symptoms started. Lab-work revealed leukocytosis (40% eosinophilia) and increased CRP (50 mg/L).
Imaging Findings
Thoracic X-ray did not show any relevant findings. Due to persistence of symptoms thoracic CT was performed, which was unremarkable except for the presence of multiple hypodense nodules in the liver parenchyma.
Abdominal CT scan post-contrast identified, at the liver parenchyma, predominantly peripheral in distribution, multiple small hypodense, hypovascular, coalescent nodularities with halo sign (peripheral contrast enhancement), some of which showing serpiginous and centripetal branching. Other findings included diffuse thickening of the gastric antrum and pyloric walls, adjacent mesenteric fat stranding and a pre-gastric intra-abdominal collection with fat stranding and peripheral enhancement, suspicious for an abscess. Along the juxta-frenic, celio-hepatic, inter-portal-cava and lumbar-aortic territories, multiple hypertrophic ganglia were seen.
Serology was performed for parasitic and viral infections and was positive for fasciola hepatica infection.
Abdominal ultrasound performed 5 days after the initiation of the treatment reveals multiple coalescent nodularities with poorly defined contours, hypoechoic, corresponding to the parasitic abscesses reported on CT.
Discussion
Fascioliasis is a food-borne zoonosis, caused by fasciola hepatica and fasciola gigantica. Although herbivores are the main hosts, they can occur in humans who ingest the organism found in fresh water plants [1].
Fasciola flukes reside in the bile ducts and spread infection through the host’s feces. After ingestion, parasites migrate through the intestine wall into the peritoneum, across the mesenteric fat and into the liver via Glissons capsule [1, 2]. The larvae then migrate into the bile ducts, where they mature and lay eggs (3-4 months after infection) [1].
Common symptoms, which occur in 80-90% of patients and usually develop 1-2 months before eggs are detectable in the stool [2], include abdominal pain, weight loss, fatigue, fever, skin rashes, dyspepsia, nausea and vomiting [3]. Elevation of liver enzymes can be seen.
Diagnosis confirmation is made either through detection of eggs on stools, liver tissue or bile drainage, or performance of serologic tests [3, 4, 5].
Two distinct stages have been described.
The parenchymal/hepatic stage is characterized by multiple small clustered hypodense lesions, found primarily near the subcapsular region of the liver and coalescing into porto-biliary or subcapsular tubular structures with serpiginous or tract-like appearance [5]. These lesions show peripheral contrast enhancement and progress centrally, representing the fluke digesting hepatocytes in its path, leaving sterile necrotic cavities and abscesses [1, 4].
Biliary involvement in fascioliasis usually manifests as cholangitis [3] and represents the biliary stage. Parenchymal lesions regress and CT demonstrates dilated biliary ducts with periportal tracking. Ductal dilation, residual parenchymal calcifications, thickening of the gallbladder wall and multiple mobile flukes in the biliary system may be seen [1, 4, 6, 7].
Imaging is fundamental in the study of fascioliasis, to provide a preliminary diagnosis and staging [5]. CT is the imaging modality of choice in the hepatic stage and the liver nodules are best seen in portal venous phase imaging [8]. US can be helpful in the biliary stage for detection of flukes, seen as mobile vermiform structures without acoustic shadowing [2, 8]. Magnetic resonance shows earlier changes on the affected organs, compared to CT [2].
Triclabendazole is used for treatment of fascioliasis, which has a cure rate of 80% [2]. In the biliary stage, endoscopic clearance of the bile ducts is mandatory [2]. Although abscesses regress, they may be present 1 year after initiation of treatment and it may be difficult to distinguish active from treated disease [8].
Differential Diagnosis List
Hepatic fascioliasis
Bacterial cholangitis
Brucellosis
Ascariasis
Other parasitic cholangitis
Primary/Secondary sclerosing cholangitis
Primary/Secondary hepato-biliary malignancies
Final Diagnosis
Hepatic fascioliasis
Case information
URL: https://www.eurorad.org/case/15667
DOI: 10.1594/EURORAD/CASE.15667
ISSN: 1563-4086
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