Isolated cysticercosis of the liver – A rare case report on diagnosis and management of an incidental finding during prepyloric perforation peritonitis repair

Abstract

Cysticercosis is one of the most common parasitic infections seen in the human population which most commonly affects the nervous system. Isolated cysticercosis of the liver is rare, and only less than five cases have been reported in the literature. Here, we describe an isolated cysticercosis of the liver. The cyst appeared as a firm nodule on the surface of the liver during a prepyloric perforation repair. The biopsy of the nodule revealed a cyst wall, and a contrast-enhanced computed tomography postoperative showed cysts in the liver. The patient was further evaluated with whole-body imaging which did not reveal any other cysts elsewhere.

INTRODUCTION

Cysticercosis is an infection caused by the larval stages of Taenia solium. Generally affecting the central nervous system, disseminated disease involving the skeletal muscles and other solid organs is also seen. Isolated cysticercosis of the liver is rare, and only a handful of cases have been reported. We present a case of cysticercosis of the liver which was incidentally found intraoperatively during a prepyloric perforation repair.

CASE REPORT

A 55-year-old male presented to the emergency surgical wing with a history of pain abdomen for 1 week, abdominal distension for 2 days, vomiting for 2 days, and not passing stool and flatus for 1 day. The pain was initially in the epigastric region and gradually progressed all over the abdomen. It was initially mild which later became severe in intensity. The vomiting was initially gastric in nature but later turned to be bilious. There was no history of melena, jaundice, or weight loss. He was a smoker for the past 40 years, and his history was not significant.

On examination, he was apprehensive with a tachycardia of 120 beats per min, respiratory rate of 22 per min, and blood pressure of 110/60 mm of hg and was afebrile. There was mild pallor. Examination of the cardiovascular and respiratory systems was normal. The abdomen was distended and tender, and there were rigidity and guarding. Bowel sounds were sluggish. There was no hepatomegaly, and the liver span was 12 cm. Per rectal examination was normal.

Blood investigation revealed a hemoglobin of 8.9 gm/dl, TLC of 4500/mm³, and platelet counts of 4.5 lack/mm³. Renal function and liver function tests were normal. ABG revealed metabolic acidosis. Abdominal X-ray revealed air under the diaphragm. After resuscitation, he was planned for exploratory laparotomy.

Intraoperatively, there was around 1 liter of biliopurulent contamination. There was a 1 cm × 1 cm prepyloric perforation. After taking the margins for a biopsy, a Cellan-Jones repair was done. A lesion was seen measuring 1 cm × 3 cm on the surface of the liver in segment VIII. It was firm in consistency, and a biopsy was taken from the edge of the lesion. He recovered well in the postoperative period. The culture from the peritoneal fluid had growth of Escherichia coli, and a culture-based antibiotic was started. He was discharged on postoperative day 5.

He was followed up in the outpatient department. His final histopathological report showed margins of the perforation site showing inflammation along with the presence of Candida [Figure 1]. He received a course of antifungal. The biopsy from the liver showed a fibrous wall of cysts with inflammation in the wall. There was a lamellated layer noted most likely due to cysticercosis [Figure 2]. This prompted us to do a contrast-enhanced computed tomography (CECT) abdomen along with the chest and head which showed multiple lesions in the liver. It was initially reported as calcified granulomas, but a review of the films after the correlation of biopsy identified them as cysticercosis [Figure 3]. No other cystic lesions were seen anywhere else in the body. A CT head along with a fundoscopy was done which did not reveal any cysts. Since the parasitic infection was asymptomatic, we had a dilemma in deciding whether to start antihelminthic therapy or not. Based on guidelines for the treatment of neurocysticercosis and previous case reports on extraneural cysticercosis, we started him on a 14-day course of albendazole along with praziquantel. He is currently kept on follow-up and is doing well at 3 months postoperative, and the follow-up CECT showed resolution of the cysts from the liver.

Figure 1.

Perforation margin showing Candida in the stomach wall (circle)

Figure 2.

Histopathology images showing the cyst wall from the liver nodule biopsy (arrow mark)

Figure 3.

Contrast-enhanced computed tomography images showing the cysts in the liver which are similar to calcifications but have lesser Hounsfield units (arrows)

DISCUSSION

Neurocysticercosis is the most common parasitic infection in human beings. Widespread dissemination of cysticerci can involve any organ or system of the body. The brain, subcutaneous tissues, skeletal muscles, lungs, eyes, liver, and rarely the heart are the organs most frequently impacted. While the majority of these organs are affected without any clinical symptoms, the brain and eyes are the only two that nearly always develop symptoms.[1] This disease, which is spread through the fecal–oral route, was common in many underdeveloped nations before globalization brought it to the rest of the world. Manifestations are produced by the mass effect of the parasite and by the immune response mounted by the host on the parasite. There are myriad clinical features and imaging findings.[2] Our patient remained asymptomatic and was only detected incidentally during surgery.

Because imaging modalities are so widely used, there are a growing number of cases of extracranial cysticercosis being diagnosed. The morphology of the cysts in extracranial cysticercosis can vary. It can present with or without an eccentric nodule, rounded cyst wall or deformed cystic wall, clear cyst, or cyst with hyperechoic contents with or without localized edema.[3] All these forms might exist simultaneously.

The imaging appearance depends on the stage of the parasite. In the active phase, plain radiography rarely shows cysticerci, but calcified cysts are apparent on plain radiographs. High-resolution ultrasound has the advantages of being a noninvasive, nonionizing modality that is quick to perform, easily repeated with minimum patient discomfort, and at a lower cost. On ultrasonography, the intramuscular cyst has the characteristic appearance of an eccentric echogenic scolex.[4] In a CECT scan, cysts might be mistaken for calcifications due to the high Hounsfield unit of the lesions. However, it has been shown that the Hounsfield units in a cyst are lesser than that of a calcification and the cyst shows mild enhancement on contrast images.[5] The resolution of lesions following antiparasitic therapy is strongly suggestive of cysticercosis. The cysts seen in the liver of our patient were reported as calcified granulomas in the initial CT report. However, only after the histopathological report was available, a reassessment of the imaging was done which confirmed cysticercosis with cysts present in multiple segments of the liver. The cysts were found to have a lower Hounsfield unit than calcifications. An MRI is superior to a CECT scan in evaluating and detecting the stage of the disease and showing perilesional edema. Typically the cyst is hypointense on T1- T1-weighted images (W1) and hyperintense on T2-weighted images. It can be oval or elliptical in shape. There is a presence of postcontrast perilesional enhancement.[4]

The blood investigations might reveal eosinophilia suggestive of helminthic infections. Serologic testing should be performed for confirmatory evaluation in patients with suspected cysticercosis.[6] The antibody test of choice is an enzyme-linked immunoelectrotransfer blot (EITB) using parasite glycoproteins performed on serum. Commercial enzyme-linked immunosorbent tests with unfractionated antigens need not be employed since comparative studies have shown that they perform poorly. The EITB is nearly 100 percent specific for Taenia solium infection. The sensitivity varies with the form of cysticercosis and the specimen. Testing serum is generally more sensitive than testing cerebrospinal fluid. Antigen-detection tests based on monoclonal antibodies are being utilized more often for monitoring and diagnosis. Negative serologic test results do not exclude the diagnosis of neurocysticercosis (NCC) in patients with compatible clinical manifestations and radiographic findings. In addition, for individuals from endemic areas, positive serologic test results may reflect previous infection and/or extraneural cysticercosis.[7,8,9]

Definitive diagnosis requires demonstration of the parasite in FNAC or biopsy specimens. This is not done routinely these days due to high-resolution imaging facilities. Eosinophils, neutrophils, palisading histiocytes, and epithelioid cell granulomas containing giant cells are all found in cytology. Parts of the parenchyma and cuticle of larvae are highly suggestive of cysticercosis. The presence of large dagger-shaped hooklets in the acute inflammatory exudate is diagnostic. Nevertheless, the obtained sample might not be representative, and the scolex and hooklets are frequently overlooked. With the advent of contemporary imaging modalities, histopathological analyses of removed material typically do not need to be performed, even though they confirm the diagnosis. A scolex with four suckers and a double row of hooklets is how it is diagnosed. To diagnose intramuscular cysticercosis, mitochondrial DNA analysis of highly calcified cysts in a histological specimen has also been utilized.[4]

Before beginning treatment, patients with confirmed cysticercosis need to have an ophthalmologic examination. The parasite will be directly visible through fundoscopy. Even though ocular cysticercosis is not very common and many patients do not experience any symptoms, inflammation around degenerating cysticerci can be dangerous to vision, especially when antiparasitic therapy is being used.[8]

The first case of isolated cysticercosis of the liver was reported by Joshua et al. in 1995.[10] Since then, there has only been a handful of cases with isolated hepatic involvement in the literature.[11,12,13] The treatment guidelines for neurocysticercosis have been established and updated by the WHO.[13] However, for extraneural isolated cysticercosis, the guidelines are not well established in the literature.[11,14] Among the four reported cases, two were from India, one from the USA, and one from Russia. In general, management of patients with symptomatic subcutaneous or intramuscular cysticerci consists of nonsteroidal anti-inflammatory medication. Excision is reasonable for symptomatic solitary lesions. Asymptomatic patients do not require specific therapy. Patients with extraneural cysticercosis should undergo radiographic imaging of the brain to evaluate for neurocysticercosis. The recommended drug regimen for neural cysticercosis is albendazole along with praziquantel for a duration of up to 14 days. The addition of steroids helps in reducing the inflammatory reactions caused due to dying parasites following anthelminthic therapy.[13] Successful treatment with albendazole has been reported for symptomatic muscular and cutaneous cysticercosis without neural involvement.[11]

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

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Conflicts of interests

There are no conflicts of interests.