Fascioliasis: A Rare Parasitic Infection-Mimicking Tumor in the Liver: Report of Two Cases
Emine ŞAMDANCI1, Nurhan ŞAHİN1, Adile Ferda DAĞLI2, Ayşe Nur AKATLI1, Nasuhi Engin AYDIN3
1Department of Pathology, İnönü University, Faculty of Medicine, Malatya, Turkey
2Fırat University, Faculty of Medicine, Elazığ, Turkey
3Katip Çelebi University, Faculty of Medicine, İzmİr, Turkey
Keywords: Fascioliasis, Liver, Hepatectomy, Charcot-Leyden crystals
Fascioliasis is a rarely encountered parasitic infection in Turkey that mainly affects the liver and bile ducts. Other defined localizations of the
parasite are the lungs, gastrointestinal system, and subcutaneous fatty tissue. Two cases of female patients who presented to the hospital with
abdominal pain and whose physical examination and laboratory findings were normal except peripheral eosinophilia, were detected to have
liver masses with necrotic areas. Segmental hepatectomies were performed in both cases with the preliminary diagnosis of liver tumors. Upon
microscopic examinations of the resection materials, necrotic granulomatous inflammation with eosinophilic reaction at the periphery and the
parasite (Fasciola hepatica) were seen. Both cases were reported to be fascioliasis according to these findings. Two cases of fascioliasis mimicking
malignancy in the liver are presented here together with literature findings.
Fascioliasis is a rare parasitic infection with a very diffuse
spread in tropical, subtropical, and temperate climate
localizations of the world and is reported in countries
that raise sheep and bovines (1). It is more common
in autumn and winter in the form of scattered cases in
humans. In Turkey, it is most frequently seen in Antalya,
Isparta, Burdur, Afyon, Konya, and its surroundings and
the lakes region (Göller Bölgesi), although the infection has
no regional features (2, 3). Its adult forms are 2-3 cm in
length. The definitive hosts are, on the other hand, humans,
sheep, goats, bovines, calves, and rabbits. The adult form
of Fasciola hepatica lives in the liver and bile ducts of the
definitive host. Eggs are excreted with the feces of the
host. Ciliated miracidia emerge from the eggs in water
and infect water snails, which are intermediate hosts. The
cercariae leave water snails and attach to a water deposit
(such as watercress) and convert into metacercariae cysts
and infect humans through the ingestion of plants that are
not washed well (4). Because of this, it is suggested that this
infection may be seen more commonly in humans, since
nature oriented nutrition has gained popularity (4).
A 26-year-old female patient presented with
abdominal pain, nausea and vomiting. Upon physical
examination, a mass was detected in the right upper quadrant. Abdominal computed tomography (CT)
revealed a multicystic mass, 6 cm in diameter in segment
5 of the liver. The gallbladder was found to be hydropic
and adhesions were observed. The patient underwent a
liver segmentectomy with a preliminary diagnosis of a
tumor. Upon macroscopic examination of the material,
a multicystic tumor-like lesion with patchy solid areas, 6
cm in diameter in the cross sections of the liver measuring
9x6x4cm was seen (Figure 1
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|Figure 1: A lesion with patchy solid segments, including
multicystic necrotic foci.
Case 2: A 52-year-old female patient presented with
abdominal pain, nausea, and vomiting. Multiple
hypodense lesions, including necrotic areas in segment
6 of the liver were seen in the abdominal CT. Positron
emission tomography (PET/CT) was performed. The PET/
CT concluded that the lesions in the liver and colon could
be malignant. A segment 6 resection, right hemicolectomy,
and cholecystectomy were performed. The macroscopic
examination revealed many mass lesions that were necrotic
and cystic in nature, with the largest diameter being 2.5
cm in the cross sections of the liver. They presented with
multiple foci, were necrotic in the middle, each measured
approximately 1 cm in diameter, and were seen in the
serosa of the colon. Tumor markers were within normal
ranges in both cases.
The microscopic examination in both cases revealed
structures of granuloma in the shape of necrotic tracts
comprised of fibrin, erythrocyte, and eosinophils with eosinophilic reaction in the peripheral region (Figure 2).
In addition, a parasite was detected in the lumen of the
necrotic tract in one of the cases (Figure 3). Additionally,
Charcot-Leyden crystals were observed in the necrotic
debris (Figure 4).
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|Figure 2: Tract-shaped granulomas, containing necrotic material
in their lumens (H&E; x40).
With the histomorphological findings, the segmental liver
materials in both cases were reported as mass lesions due to
Fasciola hepatica infection.
Fascioliasis is easy to diagnose in countries such as Egypt
and Bolivia where the infection is endemic; however, it is
difficult to diagnose the disease in countries like Turkey,
where cases are only observed sporadically (4). As for the clinical diagnosis of the disease, one must know the disease
and then suspect for it. Its seroprevalence is reported to be
2.78% in the eastern part of Turkey, independent of age,
education, and socioeconomic status. In Turkey, it is most
frequently seen in Antalya, Isparta, Burdur, Afyon, Konya,
and around the lakes region (Göller Bölgesi) (2, 3).
The final hosts of fascioliasis are humans, sheep, goats,
bovines, calves, and rabbits. The adult form of Fasciola
hepatica lives in the liver and bile ducts of the final host
and the egg is excreted with the feces. Ciliated miracidia
emerge from the eggs in the water and infect water snails
or freshwater gastropods, which are intermediate hosts.
Cercariae leave the water snails and attach to a water deposit
(such as watercress) and convert into metacercariae cysts (4).
The metacercariae emerge from the cysts when humans eat
watercress and migrate to the peritoneal cavity through the
small bowel wall and penetrate the liver capsule and enter
the liver. The larvae reach the main bile ducts and start to
spawn after their conversion to adult form (4, 5). Another
way to reach the hepatic parenchyma is through the blood
or lymphatic circulation (5).
General symptoms are abdominal pain, nausea, vomiting,
weight loss, fever, jaundice, tenderness in the location of
the liver, and eosinophilia (6). Both of the current cases had
abdominal pain. No fever was detected and both patients
had peripheral eosinophilia.
CT is helpful in the diagnosis of 90% of the cases with
fascioliasis (7). Some characteristic findings are multiple
and small hypodense lesions with indefinite borders,
microabscesses foci of demonstrating branching and
general subcapsular localization of the lesions (8, 9).
Although the CT findings of the two cases are similar, due
to the rarity of fascioliasis in this region and the absence of
clinical suspicion, both were evaluated to be tumors.
The histomorphological appearance is quite characteristic.
Granuloma structures in the shape of necrotic tracts
comprised of fibrin, erythrocyte, and eosinophils is
typical. Eosinophilic infiltration is seen in the periphery
of the granulomas. The parasite can be observed in the
lumen of the necrotic tract in fortunate cases. In addition,
Charcot-Leyden crystals are commonly seen in the necrotic
debris (10). The detection of the parasite in one of the
cases presented here specified the diagnosis and made it
easier to diagnose the case. Specific histomorphological
findings of the other case also were diagnostic. Pathologic
differentiation from other causes of inflammation (such
as tuberculosis or hydatid cyst) is important; however, it
is quite easy. The characteristic morphology of hydatid
cyst and the absence of necrotic tract formation in the
granulomas due to bacterial infections such as tuberculosis
Two rare cases of fascioliasis that created tumor-like lesions
in the liver and were easy to histomorphologically diagnose
were presented herein.
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