Surgically resected hepatic mass caused by fascioliasis

An Update on the Pathogenesis of Fascioliasis: What Do We Know?

Fasciola hepatica is a trematode parasite distributed worldwide. It is known to cause disease in mammals, producing significant economic loses to livestock industry and burden to human health. After ingestion, the parasites migrate through the liver and mature in the bile ducts. A better understanding of the parasite's immunopathogenesis would help to develop efficacious therapeutics and vaccines. Currently, much of our knowledge comes from in vitro and in vivo studies in animal models. Relatively little is known about the host-parasite interactions in humans. Here, we provide a narrative review of what is currently know about the pathogenesis and host immune responses to F. hepatica summarizing the evidence available from the multiple hosts that this parasite infects.

Charcot-Leyden crystals: An ancient but never so current discovery

From the first description of Charcot-Leyden crystals (CLCs) to the present, many steps have been taken to understand the mechanisms underlying their formation. In particular, to date not only eosinophils but also mast cells are known to be responsible for the production of CLCs, which represent the crystallized form of Galectin-10. Due to their characteristics, CLCs typically induce a crystallopathy and are responsible for an exacerbation of inflammation. Nasal cytology (NC) has allowed to better understand the correlation between the severity of several rhinopaties and the presence of CLCs in NC samples, which is strictly correlated with an eosinophiles and mast cells infiltration. As a matter of fact, rhinopaties with a mixed eosinophilic-mast cell inflammatory infiltrate, characterized by the presence of abundant CLCs, show a worse prognosis and a higher risk of relapse. This could have important therapeutic implications, since the treatments available today could be exploited to target both eosinophils and mast cells, to reduce the damage induced by CLCs.

Imaging findings of human hepatic fascioliasis: a case report and review of the literature

Background

Fascioliasis is a food-borne hepatobiliary zoonosis caused by Fasciola hepatica and Fasciola gigantica. Human infestations are predominantly seen in developing countries where the disease is endemic, but, due to the increase in international travel rates, hepatic fascioliasis is also appearing in nonendemic areas including Europe and the USA. The clinical and laboratory findings are usually nonspecific. Cross-sectional imaging can be very helpful in the diagnosis of fascioliasis as well as to differentiate it from other liver diseases with a very similar clinical picture. The objectives of this case report are to discuss imaging findings of hepatic fascioliasis and to review the literature.

Case presentation

We report the case of a 35-year-old Iranian patient who presented with right upper quadrant pain, low-grade fever, fatigue, and anorexia. The patient had a history of recent travel to the Gilan Province of Iran, almost a month before the onset of symptoms, which is an endemic area of fascioliasis in the country. Laboratory examinations revealed eosinophilia, elevated hepatic enzymes, and slightly raised C-reactive protein. Contrast-enhanced computed tomography of the patient shows clusters of focal ill-defined hypodense lesions with mild peripheral enhancement in the right liver lobe and subcapsular regions. Magnetic resonance imaging of the liver revealed multiple ill-defined lesions of low signal intensity on the T1-weighted image and high signal intensity on the T2-weighted image, extending from the liver capsule into deeper parenchyma toward periportal regions, which shows mild peripheral enhancement on post-contrast images. Imaging-based diagnosis of fascioliasis was made depending on the characteristic distribution of subcapsular tracts/lesions on the above-mentioned imaging, which was then confirmed by serologic tests using enzyme-linked immunosorbent assay. The patient was treated with triclabendazole, showing great clinical improvement, and was eventually discharged in good health condition.

Conclusion

The imaging findings in this case report highlight the importance of cross-sectional imaging for further evaluation of suspected cases of fluke-induced liver disease. The hypothesis of hepatic fascioliasis should be always considered when consistent radiological findings are observed. Clusters of tortuous subcapsular lesions with peripheral contrast enhancement extending into deeper liver parenchyma are characteristic imaging findings that strongly suggest hepatic fascioliasis.