Liver & intrahepatic bile ducts

Infectious nonviral

Fasciola hepatica


Editorial Board Member: Monika Vyas, M.D.
Deputy Editor-in-Chief: Catherine E. Hagen, M.D.
Emine Turkmen Samdanci, M.D.
Mehmet Ozcan, M.D.

Minor changes: 29 October 2021

Copyright: 2002-2021, PathologyOutlines.com, Inc.

PubMed Search: Fasciola hepatica[TI] review[PT]


Emine Turkmen Samdanci, M.D.
Mehmet Ozcan, M.D.
Page views in 2020: 1,630
Page views in 2021 to date: 1,539
Cite this page: Samdanci ET, Ozcan M. Fasciola hepatica. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/liverfasciolahepatica.html. Accessed December 4th, 2021.
Definition / general
Essential features
  • Presentation with tumor-like masses
  • Tract shaped granulomas contain necrotic material in their lumens with increased eosinophils
  • Numerous Charcot-Leyden crystals may be seen in necrosis
Terminology
  • Liver fluke or sheep liver fluke
ICD coding
  • ICD-10: B66.3 - fascioliasis
Epidemiology
  • Human infections are distributed globally, mainly in sheep rearing countries
Sites
  • Mostly liver, bile ducts and gallbladder
Pathophysiology
Etiology
Diagrams / tables

Images hosted on other servers:

Life cycle

Clinical features
  • Presentation changes according to phase of illness
    • Invasion phase: fever, hepatomegaly, upper abdominal pain, ascending bacterial cholangitis, obstructive jaundice, blood eosinophilia
    • Biliary phase: hepatomegaly, right upper quadrant pain, fever and blood eosinophilia, biliary colic, epigastric pain, fatty food intolerance, nausea, jaundice and pruritus (Burt: MacSween's Pathology of the Liver, 7th Edition, 2017)
  • Mass may present incidentally at radiologic imaging
Diagnosis
Laboratory
Radiology description
  • Ultrasound: hepatic parenchymal heterogeneity, dilatation of the bile duct with wall thickening, peripheral hypoechoic nodular lesions (Clin Microbiol Infect 2005;11:859)
  • CT / MRI: multiple, small, hypodense lesions 2 - 10 mm in diameter and microabscesses arranged in a tunnel-like branching pattern (tortuous tracts), with frequent subcapsular locations of the lesions
    • In rare instances, abscess-like lesions 7 - 10 cm in diameter can be seen and may be mistakenly considered a tumor
    • Liver capsular thickening and subcapsular hemorrhage can also be detected (Clin Imaging 2016;40:251)
Radiology images

Images hosted on other servers:

CT

PET scan

MRI

Prognostic factors
  • Capsular invasion can cause subcapsular hematomas
  • Choledochal obstruction can cause cholangitis (Res Rep Trop Med 2020;11:149)
  • Resection is mostly curative
Case reports
Treatment
Clinical images

Images hosted on other servers:

Living fasciola

Endoscopic view

Gross description
  • Solitary or multiple solid to cystic nodules with necrosis that may resemble metastases
Gross images

Images hosted on other servers:

Formalin fixed tissue

Fresh tissue

Microscopic (histologic) description
Microscopic (histologic) images

Contributed by Emine Turkmen Samdanci, M.D. and Mehmet Ozcan, M.D.
Necrotic lesions (low power field) Necrotic lesions

Necrotic lesions

Tract shaped granulomas

Tract shaped granulomas

Charcot-Leyden crystals

Charcot-Leyden crystals

Crystals in necrotic debris

Crystals in necrotic debris

Masson trichrome stain

Masson trichrome stain

Cytology description
  • Cohesive clusters of epithelioid histiocytes representing granulomas
  • Eosinophils
  • Charcot-Leyden crystals (Cytopathology 2015;26:259)
Videos

Fascioliasis caused by Fasciola hepatica

Sample pathology report
  • Liver, right hepatectomy:
    • Fascioliasis / massive necrosis (see comment)
    • Comment: When clinical, histopathological and laboratory findings are evaluated together, the case can be accepted as fascioliasis. Clinicopathological correlation is recommended.
Differential diagnosis
  • Any tumor:
    • Necrosis can be seen but eosinophils and Charcot-Leyden crystals are typically absent
    • Histologic identification of neoplastic cells
  • Echinococcus granulosus:
    • PASD / PAS positive acellular lamellar membrane and scolices
  • Echinococcus alveolaris / multilocularis:
    • Macroscopically seems more invasive, PASD / PAS positive membranes
    • Can be invasive or metastatic
  • Toxocara species:
    • Similar clinical, radiologic and histologic findings
    • Presence of pets in the history may be meaningful for Toxocara
    • Antigen tests can differentiate
  • Granulomatous infections, such as M. tuberculosis:
    • Inflammation does not contain eosinophils
Board review style question #1
Which of the following findings / complications of Fasciola hepatica is more common than others?

  1. Abdominal pain
  2. Acute pancreatitis
  3. Anaphylactic reaction
  4. Anemia
Board review style answer #1
A. Abdominal pain and fever are the most common findings. Anemia is commonly seen as a complication. The other choices can occur due to Fasciola hepatica but are not common.

Comment Here

Reference: Fasciola hepatica
Board review style question #2

A 25 year old man presents with a liver mass, which is suspicious for malignancy on imaging. PET scan shows little uptake. There is no history of malignancy and the patient denies taking any medication. A trucut biopsy is done (​shown above​) and shows necrosis, which includes eosinophils and Charcot-Leyden crystals. There are a few hepatocytes in the biopsy, which show mostly reactive changes. What is the most likely diagnosis and appropriate next step?

  1. Drug reaction, recommend discontinuation of drugs
  2. Parasite, most likely Fasciola hepatica, resection needed
  3. Tumor, biopsy must be done again to see tumor cells
  4. Tumor, resection needed
Board review style answer #2
B. Parasite, most likely Fasciola hepatica, resection needed. Charcot-Leyden crystals and eosinophils point to Fasciola hepatica. Resection is the recommended treatment.

Comment Here

Reference: Fasciola hepatica
Back to top
Image 01 Image 02