Hepatic Visceral Larva Migrans ofToxocara canis: CT and Sonographic Findings

Atypical Toxocara canis-Induced Hepatic Visceral Larva Migrans: Diagnostic Challenges and Literature Review

Toxocariasis, a zoonotic infection transmitted by Toxocara canis (from dogs) and Toxocara cati (from cats) larvae, poses rare but severe risks to humans. We present a case of hepatic visceral larva migrans (VLM) caused by Toxocara canis in a 21-year-old male with a history of close contact with a pet dog. Initial symptoms and imaging findings mimicked a pyogenic liver abscess. The initial laboratory investigations revealed neutrophilia and elevated levels of IgE. Despite broad-spectrum antibiotics, persistent fever prompted further investigation. Subsequent serological testing for Toxocara antibodies and histopathological analysis of liver tissue demonstrating eosinophil infiltrates and Charcot-Leyden crystals led to a confirmed diagnosis of a liver abscess caused by Toxocara canis. Serological testing for Toxocara antibodies and histopathological analysis of liver tissue confirmed a Toxocara canis-induced liver abscess. Albendazole treatment yielded significant clinical improvement. This case highlights the necessity of considering toxocariasis in liver abscess differentials, particularly in high-seroprevalence regions like Vietnam. Relying solely on serological tests may be insufficient, emphasizing the need for corroborative evidence, including invasive procedures like liver biopsy, for accurate hepatic toxocariasis diagnosis.

Body Imaging of Bacterial and Parasitic Zoonoses: Keys to Diagnosis

Zoonotic infections, which are transmitted from animals to humans, have been a substantial source of human disease since antiquity. As the human population continues to grow and human influence on the planet expands, humans frequently encounter both domestic and wild animals. This has only increased as deforestation, urbanization, agriculture, habitat fragmentation, outdoor recreation, and international travel evolve in modern society, all of which have resulted in the emergence and reemergence of zoonotic infections. Zoonotic infections pose a diagnostic challenge because of their nonspecific clinical manifestations and the need for specialized testing procedures to confirm these diagnoses. Affected patients often undergo imaging during their evaluation, and a radiologist familiar with the specific and often subtle imaging patterns of these infections can add important clinical value. The authors review the multimodality thoracic, abdominal, and musculoskeletal imaging findings of zoonotic bacterial (eg, Bartonella henselae, Pasteurella multocida, Francisella tularensis, Coxiella burnetii, and Brucella species), spirochetal (eg, Leptospira species), and parasitic (eg, Echinococcus, Paragonimus, Toxocara, and Dirofilaria species) infections that are among the more commonly encountered zoonoses in the United States. Relevant clinical, epidemiologic, and pathophysiologic clues such as exposure history, occupational risk factors, and organism life cycles are also reviewed. Although many of the imaging findings of zoonotic infections overlap with those of nonzoonotic infections, granulomatous diseases, and malignancies, radiologists' familiarity with the imaging patterns can aid in the differential diagnosis in a patient with a suspected or unsuspected zoonotic infection. ^© RSNA, 2023 Quiz questions for this article are available through the Online Learning Center.

Eosinophilic Granuloma of the Liver Mimicking Metastatic Liver Tumor

We herein report a case of coagulation necrosis with granulation and eosinophilic infiltration of the liver. A 37-year-old woman was diagnosed with a new mass lesion in the liver 1 month after breast cancer surgery and admitted for a further examination. Because the tumor occurred immediately after surgery, it was considered essential to determine whether or not it was a metastatic liver tumor from breast cancer. A percutaneous liver tumor biopsy revealed eosinophilic granuloma of the liver, which is considered to have a high possibility of visceral larva migrans with suspected gnathostomiasis infection. A detailed medical history and histological diagnosis are important for making a differential diagnosis.

Hepatic larva migrans presenting with upper gastrointestinal haemorrhage: A case report

Visceral larva migrans (VLM) occurs because of a host inflammatory response to the migrating larvae of a nematode. Patients usually present with fever, hepatomegaly and abdominal pain; vascular arterial complications are uncommon. A 19-year female presented with fever, jaundice, abdominal discomfort and melena. Computed tomography (CT) revealed multiple discrete, clustered, complex hepatic cystic lesions consistent with VLM, along with an arterial pseudoaneurysm from the right hepatic artery which was managed with endovascular coil embolisation.

Ultrasound and contrast-enhanced ultrasound (CEUS) in infective liver lesions

Infektiöse fokale Leberläsionen (FLL) treten in der klinischen Praxis häufig auf, wobei bakterielle Leberabszesse die Hälfte ausmachen. Eine genaue Diagnose der FLL ist für die Auswahl der am besten geeigneten Therapie und zur Vorbeugung von Komplikationen unerlässlich. Ziel der aktuellen Arbeit ist es, den Nutzen von Ultraschall und kontrastmittelverstärktem Ultraschall (CEUS) zur Erkennung und Charakterisierung infektiöser Leberläsionen zu beschreiben.

Human Toxocariasis in individuals with blood disorders and cancer patients: the first seroepidemiological study in Iran

Toxocara is one of the most prevalent nematodes in Iran, which infect humans as an intermediate host. Infection complications result from the larva migration. Human toxocariasis prevalence was various in Iran according to the area of study and population. This study was designed to evaluate the seropositivity of Toxocara IgG in patients with blood disorders and cancer patients in southwest Iran. Moreover, the study of the associated risk factors for this infection. A total of 1122 serum samples, from February 8, 2019 to August 21, 2019, including 600 healthy individuals and 522 individuals with cancer and blood disorders patients were collected. Serum samples were collected for detection of Toxocara IgG by using ELISA (Enzyme-Linked Immunosorbent Assay) kit. Sociodemographic data of all participants were collected and examined to determine their association with the infection. Out of 101 individuals with white blood cell disorders (5.94%), red blood cell disorders (7.48%) and cancer patients (11.06%) were seropositive for Toxocara IgG antibodies. The infection rate among all study population revealed that (10.76%) were positive for Toxocara IgG. This study showed the fundamental role of contact with pets and infection in groups with blood cell disorders (P-value ≤ 0.05%); while in cancer patients the association wasn't significant. Other factors such as age, location of residence, and sex showed that the association with this infection wasn't significant.

Toxocara Myopericarditis and Cardiac Magnetic Resonance Imaging in a Young Girl

Cardiac infection with Toxocara is rarely diagnosed, especially in children, and corresponding cardiac magnetic resonance imaging (CMR) has not been reported. We present a probable case, a 9-year-old girl with myopericarditis, eosinophilia, positive Toxocara serology, and CMR findings consistent with myocardial edema.

Parasitic diseases as a cause of acute abdominal pain: imaging findings

Acute abdominal pain can be seen in cases with parasitic diseases delivered to emergency departments. The diagnosis of the parasitic disease can be delayed because of the similar clinical signs encountered in other frequently seen causes of acute abdomen. Nevertheless, the features detected in imaging scans can be helpful in the diagnosis. The present study aims to raise awareness about abdominal parasitosis in emergency conditions and also to underline the association between imaging findings and the life cycle of parasites with illustrative cases.

The visceral larva migrans caused by Toxocara canis: a case report

Hepatic toxocarosis is caused by the dog´s roundworm, Toxocara canis. Responsible for an eosinophilic inflammatory syndrome causing liver damage that can be detected on ultrasound, computed tomography and sometimes magnetic resonance imaging. We report the case of a nine-year-old child, living in countryside, with a notion of cohabitation with canids. He presented a digestive symptomatology revealed by abdominal pain, with a hemeosinophilia in the hemogram. The etiological assessment of hyper eosinophilia objectified a positive Toxocara canisserology. The imaging assessment in search of digestive visceral lesions, found multiple heterogeneous hypoechogenic areas, poorly defined, scattered in the liver. On the abdominal CT scan, its areas appear of unenhanced density and low density and better visible after injection of contrast product. This observation reveals that imagery, although not very specific, helps in the assessment of liver damage from digestive toxocarosis.

Imaging of toxocariasis

Several imaging modalities have now been employed to visualize the manifestations of larval Toxocara infection in hepatic, neurologic, ocular, renal, and other anatomical sites. This report reviews the usefulness and value of these individual imaging methods in diagnosis and follow-up of the different cases causing eosinophilic (granulomatous) infiltrations the liver, lungs, brain, heart, and eyes. Imaging provides a means of assisting in diagnosis and management in this infection where diagnosis by biopsy is often unlikely to capture an actual larva for the purpose of making a definitive diagnosis on the basis of larval morphology or DNA detection.

Enhanced resolution of eosinophilic liver abscess associated with toxocariasis by albendazole treatment

BACKGROUND/AIMS

Visceral larva migrans, caused by Toxocara canis and Toxocara cati, has emerged as a significant cause of eosinophilic liver abscess (ELA). Differentiation of ELA associated with toxocariasis (ELA-T) from metastasis or primary liver malignancy is sometimes difficult. However, the role of albendazole treatment remains uncertain in this condition. The aim of this study was to evaluate whether albendazole can enhance the radiologic resolution of ELA-T.

METHODS

We retrospectively reviewed the medical records of the patients diagnosed with ELA-T at our institution between January 2008 and December 2011. ELA-T was diagnosed based on the imaging findings on computed tomography or magnetic resonance imaging and the presence of positive serum IgG antibody for Toxocara canis. Among a total of 163 patients, 32 patients received albendazole (albendazole group) and 131 did not (control group). Baseline characteristics and fate of liver nodules were compared between the two groups.

RESULTS

Baseline characteristics (age, sex, number and maximal size of lesions, eosinophil count) were similar between the two groups. Median duration for achieving radiologic resolution in the albendazole group was significantly shorter than in the control group (207 days [range 186-228] vs. 302 days [range 224-380], p=0.023). In Cox regression analysis of the cumulative rates of radiologic resolution, the hazard ratio for albendazole treatment was 1.99 (95% confidence interval, 1.22-3.23).

CONCLUSIONS

Radiologic resolution of ELA-T can be accelerated with albendazole treatment. Hence, inconvenience associated with long-term follow-up and unnecessary worries among patients can be eliminated with albendazole treatment.

Solitary Hepatic Eosinophilic Granuloma Accompanied by Eosinophilia Without Parasitosis: Report of a Case

A 43-year-old Japanese woman visited for a hepatic tumor incidentally found. We suspected eosinophilic granuloma of the liver (EGL) due to visceral larva migrans (VLM). However, neither past history nor medical interview indicated a risk of parasitosis. Blood testing revealed eosinophilia, serum examination showed normal results for immunoglobulin E, and enzyme-linked immunosorbent assay yielded negative for Toxocara and Anisakis. Gastric and colonic endoscopy revealed normal features. Several imagings showed central necrosis of the tumor. After informed consent, laparoscopic resection was performed. Histopathological examination showed EGL without parasites. No recurrence had occurred postoperatively. Most reports documented that EGL are caused by VLM. However, parasites are not always demonstrable on serum, histopathological, or immunochemical examinations. When acting as allergens to induce type I responses, microscopic agents other than parasites in the intestinal tract could induce eosinophilic inflammation in the liver. Accumulation of more cases should help clarify other pathogeneses for EGL.

Production of interleukins 4 and 10 in children with hepatic involvement in the course of Toxocara spp. infection

Toxocara spp. infestations present with a wide spectrum of symptoms, from general inflammation of internal organs with eosinophilic granuloma formulation through ocular or brain involvement. There is also an asymptomatic form. The known factors that influence the clinical form of the disease are the intensity of the infestation, the localization of the larvae, the age of the patient, the efficiency of the immune system and the history of reinfection. The aim of our study was to evaluate the production of interleukins 4 (IL-4) and 10 (IL-10) in children in the course of Toxocara spp. infections with hepatic involvement. The analysis of peripheral leucocytes, eosinophils, immunoglobulin E, and IL-4 and IL-10 concentrations presented significantly higher values in children with radiologically confirmed liver granuloma than in uncomplicated hepatomegaly. Based on statistical analysis, we confirmed the IL-4/IL-10 ratio variation in the analysed groups: patients with liver lesions showed a ratio of <1, while children without granulomas had a ratio of >2. The relevant analysis confirmed a positive statistical correlation in both seropositive groups for IgE and IL-4, and only in the granuloma group for IgE and IL-10.

Human case of visceral larva migrans syndrome: pulmonary and hepatic involvement

Visceral Larva Migrans (VLM) syndrome is commonly caused by larvae of roundworms Toxocara canis or Toxocara cati. Human toxocarosis is a soil-transmitted zoonosis, which may result in partial or general pathological changes in host tissues. We reported a case of 14-year-old boy presented with severe dry cough without dyspnea, mild chest and abdominal pain with general fatigue. Examination of peripheral blood showed marked increase in eosinophils. The chest radiography showed an infiltrative shadow in the lung fields. Chest CT demonstrated multiple opacities in both lungs. Abdominal CT showed multiple low attenuation areas in the liver. Ultrasound guided liver biopsy revealed granulomas with severe eosinophilic infiltration. The boy was treated with albendazole and responded radically. It is worth mentioning that this is the first case of hepato-pulmonary VLM syndrome in Egypt.

Hepatic visceral larva migrans, a resilient entity on imaging: Experience from a tertiary liver center

INTRODUCTION

Hepatic visceral larva migrans (VLM) is an uncommon parasitic manifestation seen in the liver. It presents as coalescing, conglomerated, or solitary abscess cavities in the liver on imaging. We conducted a retrospective clinico-radiological analysis of 24 patients with biopsy proven VLM who were reviewed and followed up at our tertiary liver institute over a period of 4 years.

MATERIALS AND METHODS

The study was performed to correlate the radiological features and imaging response to therapy for hepatic VLM. The disease course, imaging findings, progressive, absolute eosinophil counts (AEC), hydatid serology, and the extent of radiological regression of the liver lesions, on follow-up were analyzed.

RESULTS

Imaging showed a diagnostic accuracy of 42%. Hydatid serology was positive in 46% patients before starting treatment. The median pretreatment AEC of 507 showed a significant posttreatment AEC decline to median value of 117. The Wilcoxon signed ranks test showed significant decline in the AEC (P < 0.001). Radiological regression was present in all lesions. However, patients showed residual abscesses on imaging, up to 2 years on follow-up.

CONCLUSION

This study reveals that AEC has a significant predictive value in diagnosis and as a marker for disease regression. Complete radiological resolution of hepatic lesions does not correlate with total clinical remission. This finding warrants the need for further studies to look into the role of prolonged medical therapy or surgery as an alternate to current therapy module in cases of hepatic visceral larva abscesses.

Toxocariasis: A Rare Cause of Multiple Cerebral Infarction

Toxocariasis is a parasitic infection caused by the roundworms Toxocara canis or Toxocara cati, mostly due to accidental ingestion of embryonated eggs. Clinical manifestations vary and are classified as visceral larva migrans or ocular larva migrans according to the organs affected. Central nervous system involvement is an unusual complication. Here, we report a case of multiple cerebral infarction and concurrent multi-organ involvement due to T. canis infestation of a previous healthy 39-year-old male who was admitted for right leg weakness. After treatment with albendazole, the patient's clinical and laboratory results improved markedly.

The Prevalence of Toxocariasis and Diagnostic Value of Serologic Tests in Asymptomatic Korean Adults

Purpose

Toxocariasis is the most common cause of peripheral blood eosinophilia in Korea and produces eosinophilic infiltration in various organs, including the lung. However, the prevalence of toxocariasis in the general population is rarely reported.

Methods

We investigated the seroprevalence of Toxocara larval antibody among asymptomatic people who attended Samsung Medical Center for a health checkup, including low-dose chest computed tomography (CT) between March 2012 and December 2013. A total of 633 people (400 men and 233 women) were prospectively recruited.

Results

The Toxocara-seropositive rate was 51.2% using the current cutoff value based on Toxocara enzyme-linked immunosorbent assay (ELISA) (67.0% for men and 24.0% for women). In the multivariate-adjusted model, age (odds ratio [OR], 1.08; 95% confidence intervals [CI], 1.04-1.11), male sex (OR, 3.47; 95% CI, 2.26-5.33), rural residence (OR, 1.55; 95% CI, 1.05-2.30), and history of raw liver intake (OR, 8.52; 95% CI, 3.61-20.11) were significantly associated with Toxocara seropositivity. When subjects were divided into 3 groups using cutoff values base on weak positive and strong positive control optical densities (ODs), the ORs for peripheral blood eosinophilia and serum hyperIgEaemia were 0.31 (95% CI, 0.02-2.89) in the weakpositive group and 36.64 (95% CI, 11.73-111.42) in the strong positive group compared to the seronegative group. Similarly, ORs for the solid nodule with surrounding halo were 2.54 (95% CI, 0.60-10.84) in the weak positive group and 15.08 (95 CI 4.09-55.56) in the strong positive group compared to the seronegative group.

Conclusions

The study indicated that the Toxocara-seropositive rate obtained by using the current cutoff value based on ELISA was high in the asymptomatic population in Korea. The results of this study suggest that active toxocariasis may be more frequently seen in the Toxocara-strong positive group than in the Toxocara-weak positive group.

[Cardiovascular manifestations of human toxocariasis]

Toxocariasis is a parasitic infection produced by helminths that cannot reach their adult stage in humans. For their etiological species (Toxocara canis and Toxocara cati), man is a paratenic host. Infection by such helminths can produce a variety of clinical manifestations, such as: visceral larvae migrans syndrome, ocular larvae migrans syndrome and covert toxocariasis. In the visceral larvae migrans syndrome, the organs that are mainly involved include liver, lungs, skin, nervous system, muscles, kidneys and the heart. Regarding the latter, the importance of cardiovascular manifestations in toxocariasis, as well as its clinical relevance, has increasingly begun to be recognized. The current article is based on a systematic information search, focused mainly on the clinical and pathological aspects of cardiovascular manifestations in toxocariasis, including its pathophysiology, laboratory findings, diagnosis and therapeutical options, with the objective of highlighting its importance as a zoonosis and its relevance to the fields of cardiovascular medicine in adults and children.

Visceral larva migrans syndrome: analysis of serum cytokine levels in children with hepatic lesions confirmed in radiological findings

Human toxocariasis is a helminth zoonosis resulting from accidental infection of humans by the roundworms Toxocara canis (T. canis) and cati (T. cati). The infection occurs in five forms: systemic (VLM), ocular, neurological, covert and asymptomatic. The aim of this study was to characterize the radiological and immunological findings in hepatic inflammation during the course of systemic infection by Toxocara sp. in children. Fifteen children, 2 to 17 years of age, with serological diagnosis of T. canis infection underwent abdominal ultrasonography and computer tomography (CT). Eosinophil counts, immunoglobulin E titres, interleukins IL-1α, IL-4, Il-6, IL-10 and interferon gamma were measured for all patients. Abdominal ultrasound revealed multiple hypoechoic areas in the livers of all patients. On the CT images, the hepatic lesions were seen as multiple, ill-defined, oval low-attenuating nodules that measured 6 to 9 millimetres in diameter. The nodules were usually best seen in the portal venous phase and were not seen on arterial-phase images. Significant intergroup differences were observed in the concentrations of IL-1α, IL-4, IL-6 and IL-10. The level of IFN-γ was not significantly elevated in patient sera relative to controls. The analysis shows that the production of anti-inflammatory cytokines is insufficient for granuloma formation in children presenting liver lesions in the course of VLM.

Visceral larva migrans presenting as multiple liver abscesses

Eosinophilic necrotizing granulomas in the liver, known as visceral larva migrans (VLM), are a rare cause of liver abscesses. The term VLM refers to infections in human tissues caused by the larval stages of ascarid worms of dogs and cats. We report two cases of VLM which presented with high grade fever and abdominal pain for 3-4 months. Marked peripheral eosinophilia, multiple confluent perivenous lesions in the right lobe of liver with characteristic migratory tracts on imaging and biopsy evidence of necrotizing eosinophilic granulomas led to the diagnosis. Complete recovery was achieved with repeated courses of a combination of anthelmintics.

Clinical characteristics that distinguish eosinophilic organ infiltration from metastatic nodule development in cancer patients with eosinophilia

BACKGROUND

When new space-occupying lesions are observed together with peripheral blood eosinophilia in patients diagnosed with cancer, the possibility of eosinophilic organ involvement should be differentiated from metastasis of primary cancer, since a misdiagnosis could lead to unnecessary chemotherapy. The aim of this study is to identify the clinical characteristics of eosinophilic organ involvement that distinguish it from distant metastasis in patients with primary cancer.

METHODS

The medical records of 43 cancer patients who developed hepatic or pulmonary nodules with peripheral blood eosinophilia between January 2005 and February 2010 in the Asan Medical Center (Seoul) were reviewed. Eosinophilic infiltration and distant metastasis were identified on the basis of pathological findings and radiological features. Fisher's exact test, χ² test or Mann-Whitney test were used for statistical analysis.

RESULTS

In total, 33 patients (76%) were diagnosed with eosinophilic infiltration, 5 (12%) with cancer metastasis and 5 (12%) had undetermined diagnoses. Compared to the patients with metastases, the patients with eosinophilic infiltration were significantly more likely to have serology indicating a parasitic infection, a history of eating raw food, high serum levels of total IgE, normal liver function, normal C-reactive protein levels, a normal erythrocyte sedimentation rate, and fewer and smaller nodules. The most common underlying malignancy in the eosinophilic organ infiltration group was stomach cancer. Physicians tended to neglect the eosinophilia in patients with a history of cancer.

CONCLUSIONS

Several clinical characteristics of eosinophilic organ infiltration distinguish it from cancer metastasis. Physicians should make greater efforts to determine the causes of organ involvement with peripheral blood eosinophilia, especially in cancer patients.

Visceral larva migrans associated with earthworm and gecko ingestion: a case report

Introduction

Visceral larva migrans is a syndrome caused by an infection with larval helminths, which may result in partial or general pathological changes in host tissues. Due to the difficulty in finding the causative parasites, the diagnosis of visceral larva migrans is generally based on compatible clinical signs, epidemic history, marked eosinophilia and pathological examination, especially positive serological test results and the disappearance of symptoms after specific treatment.

Case presentation

We report here the case of a 21-year-old Chinese man who, having ingested living earthworms and geckos at a witch’s suggestion, presented with fatigue and wordlessness lasting for one year along with elevated transaminase levels for one month. Clinical examination showed eosinophilia, elevated transaminase levels, nodular lesions in his liver and typical pathological characteristics of hepatic visceral larva migrans. After four courses of anthelmintic therapy, our patient presented with sustaining improvement of clinical manifestations and normalization of laboratory data.

Conclusions

Because of the difficulty in making a definite diagnosis, anthelmintic therapy should be performed in patients with a suspected diagnosis of visceral larva migrans based on their epidemic history and presence of typical manifestations, especially when the serological test results are negative. Furthermore, patients with severe parasite infection may require multiple anthelmintic therapies in order to eliminate the parasites.

Transmission of Toxocara canis via ingestion of raw cow liver: a cross-sectional study in healthy adults

The aim of this study is to ascertain the relationship between ingestion of raw cow liver and Toxocara canis infection. A total of 150 apparently healthy adults were divided into 2 groups; 1 group consisted of 86 adults with positive results of Toxocara ELISA, and the other group of 64 adults with negative results. One researcher collected the history of ingestion of raw cow liver within 1 year and recent history of keeping dogs. Among 86 seropositive adults for T. canis, 68 (79.1%) had a recent history of ingestion of raw cow liver. Multivariate statistical analysis showed that a recent ingestion of raw cow liver and keeping dogs were related to an increased risk of toxocariasis (odds ratios, 4.4 and 3.7; and 95% confidence intervals, 1.9-10.2 and 1.2-11.6, respectively). A recent history of ingestion of raw cow liver and keeping dogs was significantly associated with toxocariasis.

Focal eosinophilic necrosis on superparamagnetic iron oxide-enhanced MRI

OBJECTIVE

The purpose of our study was to evaluate the usefulness of superparamagnetic iron oxide (SPIO)-enhanced MRI for distinguishing focal eosinophilic necrosis (FEN) from hepatic metastasis.

MATERIALS AND METHODS

Forty-one cases of FEN in 41 patients and 40 hepatic metastases in 40 patients were analyzed on unenhanced and SPIO-enhanced T2-weighted MRI retrospectively. Depending on the extent of the remaining hyperintense area on SPIO-enhanced T2-weighted images compared with the unenhanced images, the lesions were classified into four categories--category 1, less than 25%; category 2, 25-49%; category 3, 50-75%; and category 4, more than 75%--by two independent readers. Contrast-to-noise ratio (CNR) was measured using the same region of interest on unenhanced and SPIO-enhanced T2-weighted images. In three pathologic specimens of FEN, the number of Kupffer cells was compared with that of background hepatic parenchyma.

RESULTS

All metastases were classified as category 4, whereas FEN showed various distributions overall (category 1, 45.2%; category 2, 24.6%; category 3, 13.4%; category 4, 17.1%). FEN showed a decrease in CNR (from 7.9 +/- 5.8 to 6.1 +/- 5.6, p < 0.05), and metastases showed an increase in CNR (from 33.7 +/- 27.0 to 55.0 +/- 44.3, p < 0.05) after SPIO administration. In biopsy specimens, FEN had many more Kupffer cells (174.7 +/- 120.3 cells/high-power field [hpf]) than background hepatic parenchyma (23.7 +/- 9.8 cells/hpf). When using signal loss categories 1, 2, or 3 or CNR decrease, the accuracy of SPIO enhancement was 88.3%.

CONCLUSION

Unlike hepatic metastases, most of the cases of FEN showed a reduction in the extent of hyperintense area or a decrease in CNR after SPIO administration on the T2-weighted images. Therefore, SPIO-enhanced T2-weighted MRI can help to differentially diagnose FEN from metastases.

Toxocariasis might be an important cause of atopic myelitis in Korea

Atopic myelitis is defined as myelitis with atopic diasthesis but the cause is still unknown. Toxocariasis is one of the common causes of hyperIgEaemia that may lead to neurologic manifestations. The purpose of this study was to evaluate the sero-prevalence of Toxocara specific IgG Ab among the atopic myelitis patients. We evaluated the medical records of 37 patients with atopic myelitis whose conditions were diagnosed between March 2001 and August 2007. Among them, the 33 sera were analyzed for specific serum IgG Ab to Toxocara excretory-secretory antigens (TES). All of 37 patients had hyperIgEaemia. Specific IgE to D. pteronyssinus and D. farinae was detected in 22 (64.7%) and 34 (100%) patients, respectively, of the 34 patients. Thirty-one of 33 patients (93.9%) were found to be positive by TES IgG enzyme-linked immunosorbent assay (ELISA). Based on the image findings of eosinophilic infiltrations in the lung and liver, 8 patients had positive results. These results inferred that the prevalence of toxocariasis was high in patients with atopic myelitis. Our results suggest that toxocariasis might be an important cause of atopic myelitis and Toxocara ELISA is essential for evaluating the causes of atopic myelitis.

MRI findings of spinal visceral larva migrans of Toxocara canis

PURPOSE

The purpose of this study is to investigate the MRI findings of visceral larva migrans (VLS) of Toxocara canis in spinal cord.

MATERIALS AND METHODS

We retrospectively reviewed spinal MRI findings in eight patients with serologically proven Toxocara canis between 2005 and 2008. We evaluated the location, length, extent and migration of the lesion, MR signal intensity (SI), enhancement pattern, and swelling of the spinal cord. We evaluated clinical features including presenting symptoms and signs and treatment response.

RESULTS

Total 8 patients (M=8; age range 36-79 years) were included. The lesions were located in the cervical or thoracic spinal cord in all patients. All lesions showed high SI and minimal or mild swelling of involved spinal cord on T2WI and focal nodular enhancement on posterior or posterolateral segment of spinal cord. The length of involved lesion was relatively short in most patients. There was a migration of lesion in one patient. In spite of albendazole or steroid treatment, neurological symptoms or signs were not significantly improved in all patients.

CONCLUSION

Although all lesions show non-specific imaging findings like non-tumorous myelopathy mimicking transverse myelitis, single lesion, focal nodular enhancement on posterior or posterolateral segment of spinal cord, relatively short segmental involvement and migration of lesion may be characteristic findings of spinal VLM of Toxocara canis. In addition, the reluctant response to the treatment may be characteristic of spinal VLM of Toxocara canis.

Toxocariasis and ingestion of raw cow liver in patients with eosinophilia

Ingestion of raw animal liver has been suggested as a possible mode of infection of human toxocariasis. We evaluated the relationship between toxocariasis and the ingestion of raw meat in patients with eosinophilia of unknown etiology. The study population consisted of 120 patients presenting with peripheral blood eosinophilia (>500 cells/microliter or >10% of the white blood cell count). They were divided into 2 groups: 104 seropositive patients based on a Toxocara excretory-secretory IgG ELISA and 16 seronegative patients. While 25.0% of seronegative patients had a recent history of eating raw cow liver, 87.5% of seropositive patients had this history. Multivariate statistical analysis showed that a recent history of eating raw cow liver was related to an increased risk of toxocariasis. Collectively, it is proposed that raw cow liver is a significant infection source of toxocariasis in the patients with eosinophilia of unknown etiology.

Toxocariasis of the liver: visceral larva migrans

Toxocariasis is caused by dog ascarid, Toxocara canis, forming eosinophilic inflammation such as eosinophilic abscess or granuloma in the liver and lungs. The lesions move slowly and thus the disease is called as visceral larva migrans. On CT or MR imaging, hepatic lesions are seen as multiple, ill-defined, oval lesions that measure 1.0-1.5 cm in diameter. Sometimes, the lesion may be angular or trapezoid. The lesions are usually best seen on the portal venous phase in dynamic contrast-enhanced CT and MR imaging; the lesions are either not seen or only faintly seen on arterial and equilibrium phases. Either an enhancing rim or enhancing nodules are sometimes observed. On sonography, the lesions appear as multiple, small, oval hypoechoic lesions in the liver parenchyma. The lesions differ from metastatic nodules is as much as they have fuzzy margins, are uniform in size, non-spherical shape and are best seen on portal venous phase. On follow-up imaging, the lesions may improve, or sometimes a change positions, reflecting migration of larva in the liver, supporting the phenomenon of visceral larva migrans.

Parasitic diseases in the abdomen: imaging findings

Parasitic diseases of the liver and biliary tract include echinococcosis, schistosomiasis, toxocariasis, clonorchiasis, and opisthorchiasis, affecting millions people in some endemic areas. Amebiasis and ascariasis are believed to be the most common bowel lumen indwelling parasitic diseases, affecting billions people worldwide, but sometimes these parasites migrate inadvertently to the liver and biliary tract, resulting in liver abscess or obstructive jaundice. Imaging findings of these parasitic diseases are fairly characteristic and easy to recognize if radiologists are aware of the findings, especially in endemic areas. Because of increased immigration and frequent travelling, some patients with "exotic" parasitic diseases may be encountered in non-endemic areas, and the diagnosis may be delayed or difficult, and it is often made only after operation. This feature section was designed to provide the detailed imaging features of common parasitic diseases affecting the abdominal organs and peritoneal cavity, based on pathology-image correlation.