Extrahepatic alveolar echinococcosis without liver involvement: a rare manifestation

Primary intramuscular and intermuscular Echinococcal disease of the iliopsoas and sartorius muscles: A case report

Hydatid disease is a parasitic infection caused by the Echinococcus tapeworm. Classically, Echinococcal lesions are slowly growing cystic masses with daughter cysts. The most common sites of disease are the liver in 75% of cases and lungs in 15% of cases. This report covers a case of a patient from Southeast Europe with primary extrahepatic hydatid disease in and along the left iliopsoas and sartorius muscles. Retroperitoneal and soft tissue Echinococcus infection without liver involvement is extremely rare and creates a diagnostic challenge for clinicians and radiologists, especially in nonendemic areas.

Alveolar echinococcosis in immunocompromised hosts

BACKGROUND

Alveolar echinococcosis (AE) results of an infection with the larval stage of Echinococcus multilocularis. It has been increasingly described in individuals with impaired immune responsiveness.

OBJECTIVES

This narrative review aims at describing the presentation of AE according to the type of immune impairment, based on retrospective cohorts and case reports. Implications for patient management and future research are proposed accordingly.

SOURCES

Targeted search was conducted in PubMed using ((alveolar echinococcosis) OR (multilocularis)) AND ((immunosuppressive) OR (immunodeficiency) OR (AIDS) OR (solid organ transplant) OR (autoimmunity) OR (immune deficiency)). Only publications in English were considered.

CONTENT

Seventeen publications were found, including 13 reports of 55 AE in immunocompromised patients (AE/IS) and 4 retrospective studies of 755 AE immunocompetent patients and 115 AE/IS (13%). The cohorts included 9 (1%) solid organ transplantation (SOT) recipients, 2 (0.2%) HIV patients, 41 (4.7%) with chronic inflammatory/autoimmune diseases (I/AID) and 72 (8.3%) with malignancies. SOT, I/AID and malignancies, but not HIV infection, were significantly associated with AE (odds ratios of 10.8, 1.6, 5.9, and 1.3, respectively). Compared to AE immunocompetent patients, AE/IS was associated with earlier diagnosis (PNM stages I-II: 49/85 (58%) vs. 137/348 (39%), p < 0.001), high rate of atypical imaging (24/50 (48%) vs. 106/375 (28%), p < 0.01), and low sensitivity of serology (19/77 (25%) vs. 265/329 (81%), p < 0.001). Unusually extensive or disseminated infections were described in SOT and I/AID patients.

IMPLICATIONS

Patients who live in endemic areas should benefit from serology before onset of a long-term immunosuppressive therapy, even if the cost-benefit ratio has to be evaluated. Physicians should explain AE to immunocompromised patients and think about AE when finding a liver lesion. Further research should address gaps in knowledge of AE/IS. Especially, extensive and accurate records of AE cases have to be collected by multinational registries.

Alveolar echinococcosis as a cause of vertebral osteomyelitis and soft tissue infection with recurrent cutaneous fistula formation

Echinococcus multilocularis is endemic in Germany. However, alveolar echinococcosis is a rare disease. Most commonly the parasite affects the liver, behaving like a malignant tumour. Bones are affected in less than 2% of cases. We report a case of vertebral osteomyelitis accompanied by recurrent cutaneous fistula formation.

Hepatic Alveolar Echinococcosis

Hepatic alveolar echinococcosis (HAE) is a rare but severe zoonosis caused by the pseudotumoral intrahepatic development of the larval stage of the tapeworm Echinococcus multilocularis. HAE is present only in the Northern Hemisphere, predominantly in China. Currently, there is a significant resurgence of cases in historically endemic areas associated with emergence of HAE in countries not previously concerned. Today, in European countries, HAE is often discovered by chance; however, clinicians should be made aware of opportunistic infections that progressively emerged recently as a result of therapeutic or pathological immunosuppression. Ultrasonography is the key first-line diagnostic procedure, with specific serology providing confirmation in 95% of the cases. Albendazole, only parasitostatic, is the mainstay for treatment. Surgical resection, if feasible, is the gold standard for treatment, and more patients are currently eligible for this option because of an earlier diagnosis. The prognosis has considerably improved but remains poor in countries where access to care is less favorable.

Intrahepatic manifestation and distant extrahepatic disease in alveolar echinococcosis: a multicenter cohort study

BACKGROUND

The main endemic areas of alveolar echinococcosis (AE) are in central Europe and western China. The infiltration of intrahepatic vascular and bile ducts as well as extrahepatic disease can lead to complications and may increase morbidity in AE.

PURPOSE

To evaluate the vascular/biliary involvement of hepatic alveolar echinococcosis (HAE) and distant extrahepatic disease at each of four locations in Germany, France, and China.

MATERIAL AND METHODS

Contrast-enhanced abdominal magnetic resonance imaging (MRI) scans of patients with HAE, 200 in total, were evaluated by five examiners. AE liver lesions were classified according to Kodama's classification. Furthermore, distant extrahepatic manifestations were documented with additionally performed imaging modalities. Vascular/biliary involvement of hepatic manifestations as well as the presence of extrahepatic manifestations were correlated with the respective Kodama type of the liver lesion.

RESULTS

Distant extrahepatic AE manifestations were significantly more frequent in China than in Europe (12/100 vs. 3/100; Fisher's exact test: P=0.0286). A significant relationship exists between presence of distant extrahepatic disease manifestation and size of the AE liver lesion (132.53 ± 48.65 vs. 92.49 ± 50.06; P = 0.0030). Vascular/biliary involvement is significantly more frequent in China than in Europe (86/100 vs. 65/100; χ² = 11.92; P = 0.0006). Vascular/biliary involvement depends on lesion size (111.10 ± 47.44 vs. 47.36 ± 24.36; P<0.0001). Different types of AE liver lesions are associated with differences in vascular/biliary involvement and extrahepatic manifestations.

CONCLUSION

Vascular/biliary involvement and presence of distant extrahepatic manifestations depend on size of the HAE lesions and are more frequently detected in China. Different MRI morphological patterns influence vascular/biliary involvement and the occurrence of distant extrahepatic manifestations.

Clinical Features, Radiological Characteristics, and Outcomes of Patients With Intracranial Alveolar Echinococcosis: A Case Series From Tibetan Areas of Sichuan Province, China

Objectives: Intracranial alveolar echinococcosis (IAE), a zoonotic disease, is a critical health problem in the Tibetan region. We aimed to describe the clinical and radiological characteristics and outcomes among patients with IAE.

Methods: We screened patients diagnosed with IAE between March 2015 and May 2019 at the Ganzi Tibetan Autonomous Prefecture People's Hospital. Detailed demographics, clinical characteristics, neuroimaging features, and outcomes were recorded.

Results: A total of 21 patients with an average age of 44.1 ± 12.7 years were included. Thirteen (61.9%) patients were male. The most common chief neurological complaint was headache (n = 17, 81.0%), followed by dizziness, seizure, visual disturbances, hemiparesis, disturbed consciousness, and dysphasia. All the patients had coexisting liver localizations. The typical neuroimaging features of IAE on cerebral magnetic resonance imaging scans showed obvious low-signal shadow with multiple small vesicles inside the lesions on T2-weighted images and FLAIR images. The pathological HE staining demonstrates vesicular lesions with several internal sacs. For hepatic alveolar echinococcosis (AE), the hepatic portal was invaded in six (28.6%) patients, and the portal vein (n = 5, 23.8%) was the mostly commonly involved vessel. As for treatment, 11 patients (52.4%) had poor compliance with albendazole. The duration of patients taken albendazole ranged from 2 months to 3 years. Cerebral AE surgery was performed in 11 patients, five of them underwent partial resection of AE lesions, and six patients received total resection. One patient with primary IAE underwent radical surgery. Ten patients (47.6%) died during the follow-up for a mean of 21.7 ± 11.9 (3–46) months. In total, 28.9% of the patients died within 5 years, and 71.6% died within 10 years. The median interval between the date of diagnosis as AE and death was 84 (19–144) months.

Conclusion: Despite substantial advances in diagnostic and therapeutic methods, the treatment of IAE remains difficult and results in unsatisfactory outcomes. The major critical issue is surgical treatment of IAE although the disease is disseminated. Besides, lifelong albendazole would be indicated, but most patients had poor medication compliance. It is important to educate patients about the necessity of medical treatment.

Difficulties in diagnosing the alveolar echinococcosis (case report)

•

Alveolar echinococcosis is asymptomatic usually and detected an advanced stage.

•

Differential diagnosis is difficult due to similarities with tumor and metastasis to the different organs.

•

The cystic mass size can be very large.

•

The resection and albendazole is beneficial.

Introduction

Alveolar echinococcosis is dangerous parasitic zoonose with the large endemic area. This disease has a high prevalence in Kazakhstan.

Presentation of case

We report on a 45-year woman suffering from alveolar echinococcosis with a huge cystic mass and difficulty of differential diagnosis. She was hospitalized for surgery with primary diagnosis of hydatid disease. The liver carcinoma was suspected during surgery due to the huge size and structure of the mass. This mass was totally removed. The alveolar echinococcosis was confirmed by histopathological examination.

Discussion

Essential features of this case are the large size of the lesion with a dense consistency and the germination of blood vessels, which unusual for alveolar echinococcosis. Total resection and Albendazole therapy was successful for patient, she didn't have a relapse during the follow-up examination.

Conclusion

This report may provide new aspects of visualization of alveolar echinococcosis and highlight the necessity for the upgrade of the diagnosis tactic.

Evaluation of intrahepatic manifestation and distant extrahepatic disease in alveolar echinococcosis

BACKGROUND

The main endemic areas of alveolar echinococcosis (AE) are in Central Europe and Western China. Both the infiltration of intrahepatic vascular and bile duct structures as well as extrahepatic disease can lead to further complications and may increase morbidity in patients with AE.

AIM

To evaluate vascular/biliary involvement in hepatic AE and its distant extrahepatic disease manifestations in an international collective was the aim.

METHODS

Consecutively, five experienced examiners evaluated contrast-enhanced abdominal computed tomography (CT) scans for 200 patients with hepatic AE of each of four locations (n = 50) in Germany, France and China. Therefore, we retrospectively included the 50 most recent abdominal contrast-enhanced CT examinations at each center, performed because of hepatic AE from September 21, 2007 to March 21, 2018. AE liver lesions were classified according to the echinococcosis multilocularis Ulm classification for CT (EMUC-CT). Distant extrahepatic manifestations were documented either by whole body positron emission tomography–CT or with the addition of thoracic CT and cranial magnetic resonance imaging. Vascular/biliary involvement of the hepatic disease as well as the presence of distant extrahepatic manifestations were correlated with the EMUC-CT types of liver lesion. Statistical analysis was performed using SAS Version 9.4 (SAS Institute Inc., Cary, NC, United States).

RESULTS

Distant extrahepatic AE manifestations were significantly more frequent in China than in Europe (P = 0.0091). A significant relationship was found between the presence of distant extrahepatic disease and AE liver lesion size (P = 0.0075). Vascular/biliary structures were involved by the liver lesions significantly more frequently in China than in Europe (P < 0.0001), and vascular/biliary involvement depended on lesion size. Different morphological types of AE liver lesions led to varying frequencies of vascular/biliary involvement and were associated with different frequencies of distant extrahepatic manifestations: Vascular/biliary involvement as a function of lesions primary morphology ranged from 5.88% of type IV liver lesions to 100% among type III lesions. Type IV differed significantly in these associations from types I, II, and III (P < 0.0001). With respect to extrahepatic disease, the primary morphology types IV and V of liver lesions were not associated with any case of distant extrahepatic disease. In contrast, distant extrahepatic manifestations in types I–III were found to varying degrees, with a maximum of 22% for type III.

CONCLUSION

Different CT morphological patterns of hepatic AE lesions influence vascular/biliary involvement and the occurrence of distant extrahepatic manifestations. There are intercontinental differences regarding the characteristics of AE manifestation.

A case of Echinococcus granulosus hepatic hydatid cyst together with pyogenic liver abscess in a Nepali patient

Hydatidic disease (echinococcosis) is a significant health problem in Nepal. In humans, mainly involves liver and commonly remains silent without symptoms or causing only mild pressure symptomatology. However, inadequate invasive medical procedures may cause the rupture of the cyst with serious complications, anaphylactic shock and death. Herein, we report the case of a Nepali patient who had been treated of a hepatic abscess with percutaneous drainage and antibiotics in a previous hospitalization. Study by drain fluid, ultrasonography and the magnetic resonance imaging revealed the presence of an intact Hydatidic cyst in the liver concomitantly with a percutaneously draining abscess (with free hooklets and a drain tube). This emphasizes the importance of putting the Hydatidic cyst into the differential diagnosis of liver abscess, especially in non-endemic areas.

Spinal Hydatid Cyst Disease : Challenging Surgery - an Institutional Experience

Objective

Hydatid cyst disease is caused by the parasite Echinococcus granulosus. It is rarely seen in the vertebral system, occurring at a rate of 0.2–1%. The aim of this study is to present 12 spinal hydatid cyst cases, and propose a new type of drainage of the cyst.

Methods

Twelve cases of spinal hydatid cysts, surgical operations, multiple operations, chronic recurrences, and spinal hydatic cyst excision methods are discussed in the context of the literature. Patients are operated between 2005 and 2016. All the patients are kept under routine follow up. Patient demographic data and clinicopathologic characteristics are examined.

Results

Six male and six female patients with a median age of 38.6 at the time of surgery were included in the study. Spinal cyst hydatid infection sites were one odontoid, one cervical, five thoracic, two lumbar, and three sacral. In all cases, surgery was performed, with the aim of total excision of the cyst, decompression of the spinal cord, and if necessary, stabilization of the spinal column. Mean follow up was 61.3 months (10–156). All the patients were prescribed Albendazole. Three patients had secondary hydatid cyst infection (one lung and two hepatic).

Conclusion

The two-way drainage catheter placed inside a cyst provides post-operative chlorhexidine washing inside the cavity. Although a spinal hydatid cyst is a benign pathology and seen rarely, it is extremely difficult to achieve a real cure for patients with this disease. Treatment modalities should be aggressive and include total excision of cyst without rupture, decompression of spinal cord, flushing of the area with scolicidal drugs, and ensuring spinal stabilization. After the operation the patients should be kept under routine follow up. Radiological and clinical examinations are useful in spotting a recurrence.

Vertebral alveolar echinococcosis-a case report, systematic analysis, and review of the literature

Alveolar echinococcosis caused by Echinococcus multilocularis is an infrequent zoonosis with a high degree of disability, morbidity, and mortality, especially in disease clusters of the northern hemisphere. The diagnosis is complicated by extended incubation time, diverse clinical manifestations, and mimicking of differential diagnoses. The primary organ affected is the liver, but extrahepatic disease is possible, with vertebral involvement in only a few dozen cases described worldwide. Although vertebral alveolar echinococcosis seems to be rare, it might be under diagnosed, and it might be seen more often as the number of people with immunocompromised conditions increases. Recognition of this syndrome is crucial, because advances in medical and surgical management strategies since the introduction of benzimidazole in 1976 have controlled and relieved symptoms in most cases. In this Grand Round, we present the case of a 75-year-old woman who was referred for biopsy of a lumbar lesion 3 months after she was diagnosed with chronic myeloid leukaemia. The diagnosis of hepatic alveolar echinococcosis with metastasis to the lumbar spine and paravertebral region as well as the brain was confirmed by biopsy, PCR, and serology. The patient was given albendazole and referred for palliative surgery with the aim of pain control. Clinical features of the case are presented and discussed in the context of the literature. This case and review illustrate the complexity of extrahepatic alveolar echinococcosis manifestations and the necessity of an interdisciplinary approach.

Primary cerebral alveolar echinococcosis: mycology to the rescue

A case of primary cerebral alveolar echinococcosis with a favorable outcome is reported. A universal fungal PCR enabled this diagnosis, while the initial serological analysis remained noncontributive.

Spinal cystic echinococcosis--a systematic analysis and review of the literature: part 1. Epidemiology and anatomy

Bone involvement in human cystic echinococcosis (CE) is rare, but affects the spine in approximately 50% of cases. Despite significant advances in diagnostic imaging techniques as well as surgical and medical treatment of spinal CE, our basic understanding of the parasite's predilection for the spine remains incomplete. To fill this gap, we systematically reviewed the published literature of the last five decades to summarize and analyze the currently existing data on epidemiological and anatomical aspects of spinal CE.

Spinal cystic echinococcosis (CE) is a rare but malignant form of a truly neglected tropical disease. Despite significant advances in diagnostic imaging techniques as well as surgical and medical treatment of spinal CE, our basic understanding of the parasite's predilection for the spine remains poor at best. Information on the influence of parasite and host specific factors on anatomical manifestations and evolution of CE is currently lacking. We systematically reviewed all published case reports and case series of spinal CE from 1965 until 2012 to summarize and analyze the epidemiological and anatomical aspects of the disease and discuss the findings in light of the existing data.

Skeletal manifestations of hydatid disease in Serbia: demographic distribution, site involvement, radiological findings, and complications

Although Serbia is recognized as an endemic country for echinococcosis, no information about precise incidence in humans has been available. The aim of this study was to investigate the skeletal manifestations of hydatid disease in Serbia. This retrospective study was conducted by reviewing the medical database of Institute for Pathology (Faculty of Medicine in Belgrade), a reference institution for bone pathology in Serbia. We reported a total of 41 patients with bone cystic echinococcosis (CE) during the study period. The mean age of 41 patients was 40.9±18.8 years. In 39% of patients, the fracture line was the only visible radiological sign, followed by cyst and tumefaction. The spine was the most commonly involved skeletal site (55.8%), followed by the femur (18.6%), pelvis (13.9%), humerus (7.0%), rib (2.3%), and tibia (2.3%). Pain was the symptom in 41.5% of patients, while some patients demonstrated complications such as paraplegia (22.0%), pathologic fracture (48.8%), and scoliosis (9.8%). The pathological fracture most frequently affected the spine (75.0%) followed by the femur (20.0%) and tibia (5.0%). However, 19.5% of patients didn't develop any complication or symptom. In this study, we showed that bone CE is not uncommon in Serbian population. As reported in the literature, therapy of bone CE is controversial and its results are poor. In order to improve the therapy outcome, early diagnosis, before symptoms and complications occur, can be contributive.

Extrahepatic primary adrenal alveolar echinococcosis: a review

BACKGROUND

Primary echinococcosis, and especially primary alveolar echinococcosis (AE) is rare among adrenal lesions.

METHODS

We report a case of primary AE in a 28-year-old male with low backache and occasional upper limb pain lasting for six months, and review the pertinent but sparse literature on this disorder.

RESULTS

Evaluation of the patient revealed an abdominal mass as right adrenal AE. The adrenal gland is a rare extrahepatic site of occurrence of echinococcosis, and particularly of AE. Patients with adrenal echinococcosis usually have nonspecific clinical symptoms. Imaging examinations revealed clearly the features of AE and its surrounding pathology. Alveolar echinococcosis was seen as an inhomogeneous pseudotumor with irregular boundaries, an irregular central pseudocystic appearance, and infiltration into surrounding structures. On contrast-enhanced computed tomography, the periphery of the mass in AE may be enhanced and multicentric vesicles may be seen. Magnetic resonance imaging may show the multivesicular morphology of lesions. The definitive diagnosis of AE should be confirmed by pathologic or serologic examination. Radical surgical resection of the removable parasitic lesion, followed by anti-infective therapy with benzimidazoles, is the primary method for treating AE.

CONCLUSION

Although primary adrenal AE is rare, it should be included in the differential diagnosis of adrenal masses, especially in regions where AE is endemic.

Fatal alveolar echinococcosis of the lumbar spine

For the last 10 years, the southern part of Belgium has been recognized as a low-risk area of endemicity for alveolar echinococcosis. This infection, caused by Echinococcus multilocularis, usually induces a severe liver condition and can sometimes spread to other organs. However, alveolar echinococcosis involving bones has been described only very rarely. Here, a fatal case of spondylodiscitis due to E. multilocularis contracted in southern Belgium is reported.

Recurrent hepatic alveolar echinococcosis: report of the first case in Korea with unproven infection route

Human alveolar echinococcosis (AE), a hepatic disorder that resembles liver cancer, is a highly aggressive and lethal zoonotic infection caused by the larval stage of the fox tapeworm, Echinococcus multilocularis. E. multilocularis is widely distributed in the northern hemisphere; the disease-endemic area stretches from north America through Europe to central and east Asia, including northern parts of Japan, but it has not been reported in Korea. Herein, we represent a first case of AE in Korea. A 41-year-old woman was found to have a large liver mass on routine medical examination. The excised mass showed multinodular, necrotic, and spongiform appearance with small irregular pseudocystic spaces. Microscopically, the mass was composed of chronic granulomatous inflammation with extensive coagulation necrosis and parasite-like structure, which was revealed as parasitic vesicles and laminated layer delineated by periodic acid-Schiff (PAS) stain. Clinical and histologic features were consistent with AE. After 8 years, a new liver mass and multiple metastatic pulmonary nodules were found and the recurred mass showed similar histologic features to the initial mass. She had never visited endemic areas of AE, and thus the exact infection route is unclear.

Clinical features and evolution of alveolar echinococcosis in France from 1982 to 2007: results of a survey in 387 patients

BACKGROUND & AIMS

Alveolar echinococcosis (AE) is a rare disease in humans, caused by the larval stage of the fox tapeworm Echinococcus multilocularis.

METHODS

We present here 387 detailed AE cases diagnosed in France from 1982 to 2007 actively identified by a retrospective survey performed in 1997-1998 and prospectively thereafter.

RESULTS

Male:female ratio was 1.03 and mean age 57.8 years at time of diagnosis. Among the 362 complete files (including 347 non dead-out and 15 dead-out lesions), 73% of the patients were symptomatic at first admittance. Among them, 83% presented with clinical patterns evocative either of a digestive or a hepatic disorder. Other symptomatic patients presented with erratic clinical pictures, generally due to metastasis or extra-hepatic location of the parasite. Except for a few patients with particularly severe AE who died shortly after the diagnosis, most patients were treated using benzimidazoles. Their mortality tends to merge with that of the general French population, matched by sex, age, and calendar year. This study also highlights an unexpectedly high frequency of blood-tied family cases (13% of patients submitted to a specific questionnaire).

CONCLUSIONS

Even though the broad set of clinical features provoked by E. multilocularis makes AE a potential diagnostic trap for many physicians, our study revealed an improvement of its prognosis. However, as shown by our findings about the frequency of family cases, there is still a need for studies aimed at better describing this uncommon parasitic disease.

Case studies emphasising the difficulties in the diagnosis and management of alveolar echinococcosis in rural China

Background

Human alveolar echinococcosis (AE) is caused by the accidental ingestion of the eggs of the fox tapeworm Echinococcus multilocularis. AE occurs frequently in rural western China due to the poor levels of hygiene, the close contact of people with dogs, and the lack of appropriate facilities for the correct and rapid diagnosis of the disease.

Findings

We describe a case of a patient with hepatic AE, and AE metastases of the brain. She was mistakenly diagnosed with suspected undifferentiated metastatic cancer of the liver and brain, and with a pulmonary bacterial infection, but was subsequently correctly diagnosed during a follow-up field survey for echinococcosis. The diagnosis of brain AE was confirmed by pathological examination of tissue biopsies removed during neurosurgery. We also briefly describe other symptomatic and asymptomatic AE cases, identified by chance, likely due to the inadequate facilities available in rural communities in China for AE diagnosis and management, since the rapid and accurate diagnosis of metastatic AE requires a high level of expertise in the appropriate diagnostic procedures.

Conclusions

This report highlights the necessity for an upgrade in the diagnosis, treatment, prevention and control of AE in rural China.

Usefulness of gray-scale contrast-enhanced ultrasonography (SonoVue®) in diagnosing hepatic alveolar echinococcosis

Hepatic alveolar echinococcosis (HAE) is a parasitic infection with an infiltrative growth pattern that has the appearance of a hepatic malignant tumor. Ultrasound (US) has been used for screening of HAE in epidemic areas. However, it has been very difficult to evaluate the clear boundary and microvessel perfusion of the lesions. The aim of this study was to demonstrate the characteristic imaging and clinical significance of HAE lesions by contrast-enhanced ultrasonography (CEUS). Seventeen patients with 19 HAE lesions were examined in sequence with US, color Doppler flow imaging (CDFI) and then CEUS before any treatment. All the data were compared before surgery. Examined by fundamental US, 47.4% of HAE lesions showed irregular hyperechoic substantive areas and 52.6% appeared as having a mixed echotype with irregular anechoic areas in the central portion of the lesions. The CDFI method indicated no blood flow signals inside any of the 19 lesions. By CEUS, all 19 lesions displayed circular rim enhancement in the peripheral segments and absent enhancement within the central areas of the lesions (a "black hole" effect). As a result, the lesions' margins were clear, irregular and distinct. In general, the sizes of all the HAE lesions observed by CEUS were larger than those obtained by fundamental US. Therefore, CEUS is a simple imaging method and can be a helpful tool for more accurate sizing of HAE lesions and their surrounding invasion range and the proper cut-off margin when radical hepatectomy is needed.

Surgical management of splenic echinococcal disease

Background

Infection of the spleen with echinococcus is a rare clinical entity. Because the diagnosis of a splenic infestation with echinococcus is sometimes delayed, large hydatid cysts or pseudotumors may develop, demanding a differential surgical approach to cure the disease.

Methods

In a retrospective study 10 patients out of 250 with abdominal echinococcosis (4%) were identified to have splenic infestation, either limited to the spleen (n = 4) or with synchronous involvement of the liver (n = 4), major omentum (n = 1), or the liver and lung (n = 1). Only one patient had alveolar echinococcosis whereas the others showed hydatid cysts of the spleen. Surgical therapy included splenectomy in 7 patients or partial cyst excision combined with omentoplasty in 3 patients. In case of liver involvement, pericystectomy was carried out simultaneously.

Results

There was no mortality. Postoperative complications were observed in 4 patients. Hospital stay and morbidity were not influenced when splenic procedures were combined with pericystectomies of the liver. Mean follow- up was 8.8 years and all of the patients are free of recurrence at this time.

Conclusions

Splenectomy should be the preferred treatment of hydatid cysts but partial cystectomy is suitable when the cysts are located at the margins of the spleen. Due to low morbidity rates, simultaneous treatment of splenic and liver hydatid cysts is recom mended.

Hepatic infestation of Echinococcus multilocularis with extension to regional lymph nodes

OBJECTIVE

The objective of this paper is to prove lymph node infestation by Echinococcus multilocularis and provide evidence for systematic lymph node dissection in curative resections for alveolar echinococcosis (AE).

BACKGROUND

Human AE is a life threatening parasitic condition, usually caused by an intrahepatic infiltrative and destructive growth of the larvae E. multilocularis. WHO guidelines provide radical hepatic resection for curative treatment. However, the current norms do not consider dissection of regional lymph nodes. No report to date has visualized concurrent lymph node infestation.

METHODS

Radical excision of infested liver including regional lymph nodes with subsequent histological examination was carried out in a patient suffering from AE. The literature was reviewed and a revised state-of-the-art treatment of AE deduced.

RESULTS

Upon inspection the liver displayed macroscopic features of AE, in contrast to the regional lymph nodes which appeared unsuspicious. Further histological analysis confirmed regional lymph node infestation of E. multilocularis.

CONCLUSIONS

This is the first publication on histological evidence of E. multilocularis in regional hepatic lymph nodes, and thus, demonstrating dissemination from the liver. Since AE can spread through lymphatic drainage, even without causing macroscopic conspicuity, resection should not be resumed to the liver tissue only, but rather to consider the routine removal of regional lymph nodes as well. Omission of lymph node dissection can leave behind parasitic tissue and surgical procedures erroneously judged as curative.

Long-term experience on surgical treatment of alveolar echinococcosis

INTRODUCTION

Alveolar echinococcosis (AE) is life-threatening and reports on surgical procedures and results are rare, but essential.

MATERIALS AND METHODS

Longitudinal surveillance and long-term follow-up of patients surgically treated for AE during the periods 1982-1999 (group A) and 2000-2006 (group B).

SETTING

University hospital within an endemic area.

RESULTS

The median (min-max) follow-up period was 141 (5-417) months. Forty-eight surgical procedures were performed in 36 patients with AE: 63% were partial resections of the liver (additional extrahepatic resection in ten of them), 17% just extrahepatic resections, 10% biliodigestive anastomosis, and 10% exploratory laparotomies. Seventy-five percent of the operations were first-time procedures, 25% done due to a relapse. Forty-two percent of the operations were estimated to be curative (R0), whereas 58% were palliative (R1, R2). All patients had additional medical treatment and periodical follow-up. Two out of 18 (11%) patients, estimated to have had curative surgery, developed a relapse 42 and 54 months later. R0-resection rates depended on the primary, neighboring, metastasis stage of AE (S1, 100%; S2, 100%; S3a, 33%; S3b, 27%; S4, 11%). During the period 2000-2006 elective radical surgery for AE was done only if a safe distance of at least 2 cm was attainable. This concept was associated with an increased R0-resection rate of 87% for group B compared to 24% for group A. Operative procedures done to control complicated courses of AE (jaundice, cholangitis, vascular compression, bacterial superinfection) have not been curative (R2) in 82% because the disease had spread into irresectable structures. Morbidity was 19%. All patients with curative resections are alive. Fifty-six percent of the patients with palliative treatment are alive as long as 14-237 months, 28% died from AE 164-338 months after diagnosis (late lethality), and 17% died due to others diseases 96-417 months after diagnosis of AE. One out of seven (14%) patients suffering from suppurative parasitic necrosis died because it was impossible to control systemic sepsis (3% hospital lethality).

CONCLUSION

Curative surgery for AE is feasible if the parasitic mass is removable entirely. The earlier the stage, the more frequent is R0 resectability. The observance of a minimal safe distance increases the rate of R0 resections. The benefit of palliative surgery is uncertain due to favorable long-term results of medical treatment alone. However, necrotic tissue is at risk of bacterial superinfection, which can cause life-threatening sepsis. Palliative surgery is an option to treat complications, which could not be managed otherwise.

Screening methods in alveolar echinococcosis: a follow-up study comparing Emc- and Emf-ELISA with Em2plus-ELISA and ultrasonography

The purpose of the present study was to identifyEchinococcus multilocularisinfection in follow-up of 95 subjects initially seropostive by Emc-ELISA or Emf-ELISA antibody assays and to compare the utility of these assays with specific Em2plus-ELISA and ultrasound screening forE. multilocularisinfection. At follow-up seven subjects were seropositive with both methods, while three were seropositive only with Emc-ELISA and 11 only with Emf-ELISA. All subjects were seronegative with Em2plus-ELISA. There were no manifestations ofE. multilocularisinfestation by ultrasonographic screening. Seropositivity on Emc-ELISA and Emf-ELISA screening tests does not appear to correlate with manifest alveolar echinococcosis identified by ultrasound. A recommendation for further follow-up of subjects found to be seropositive with Emc-ELISA and Emf-ELISA but with no sonographic evidence of disease is not justified at this time.

Imaging of Parasitic Diseases of the Thorax

A broad spectrum of parasitic infections frequently affects the lungs, mediastinum, and thoracic wall, manifesting with abnormal imaging findings that often make diagnosis challenging. Although most of these infections result in nonspecific abnormalities, familiarity with their imaging features and the diagnostic pathways help the radiologist to formulate an adequate differential diagnosis and to guide diagnosticians in reaching a definitive diagnosis.

Osseous hydatid disease

Hydatid disease is still endemic in several regions worldwide and is caused in most cases by the larval form of two species of the tapeworm Echinococcus: E. granulosus and E. multilocularis. Bone involvement is rare (0.2-4%), affecting the spine in almost half of the cases. The disease is usually silent until a complication (e.g. paraplegia or pathologic fracture) occurs. Many cases are diagnosed intraoperatively. Pre-operative diagnosis is based on radiological findings and serological assays, which lack high sensitivity and specificity. A high index of suspicion is necessary for the diagnosis, especially in patients that live in or travel to sheep-raising areas where hydatid disease is endemic. The treatment of choice is surgical, following the principles of a locally malignant lesion. Chemotherapy (albendazole alone or in combination with praziquantel) is used as an adjuvant treatment or when surgery is not possible. The prognosis is often poor, especially in the spine: most patients do not recover neurologically, the mortality and complication rate is high and many cases recur, as it is often impossible to radically excise the pathologic tissue.

The ability of67ga scintigraphy to detect the lesions ofEchinococcus multilocularis infection: Preliminary results

AIM

To assess the ability of 67Ga scintigraphy to detect the lesions of Echinococcus multilocularis (EM) infection.

MATERIALS AND METHODS

An animal model of EM infection was developed. The infected tissues taken from stock infection were placed into the abdominal cavity of uninfected animals operatively. The success of implantation was controlled 20-25 days after implantation. Five infected and 2 healthy animals were studied. All of the animals were examined by ultrasound before the scintigraphic evaluation. After the injection of 7.4 MBq (200 microCi) 67Ga citrate intravenously, static images from the whole anterior thorax and abdomen were obtained at 24, 48 and 72 hours. Visual and semiquantitative analyses were performed. In semiquantitative analysis, an irregular region of interest was drawn over the thorax as the background, excluding the heart and a second region of interest was drawn over the abdomen, excluding the liver and spleen. Abdomen/ background ratios were calculated using the mean counts.

RESULTS

In the visual evaluation, it was noticed that there was considerably increased 67Ga uptake in the abdomens of the infected animals. In infected animals, mean abdomen/background ratios at 48 and 72 hours (3.76 +/- 1.04, 4.13 +/- 0.72, respectively) were increased compared with mean abdomen/background ratios at 24 hours (2.94 +/- 0.77). These increases in abdomen/background ratios were statistically significant at 72 hours (p = 0.04). Between the infected animals and control group, mean abdomen/background ratios were compared, and statistically significant differences were found in the images obtained at 48 and 72 hours.

CONCLUSION

Imaging at 72 hours seems to be more suitable imaging time for the diagnosis of alveolar echinococcosis. 67Ga scintigraphy may successfully demonstrate the lesions of EM infection localized intraperitoneally. The method of 67Ga scintigraphy is useful because it is simple, non-invasive and relatively safe.

Magnetic Resonance Imaging of Alveolar Echinococcosis Experimentally Induced in the Rat Lung

Pulmonary alveolar echinococcosis (AE) caused by the metacestode of Echinococcus multilocularis is a lethal zoonosis and is a lesion secondarily induced by hematogenous dissemination from hepatic AE lesions. In the present study, a hematogenous pulmonary AE model was experimentally induced in rats by the injection of echinococcal larval tissue homogenate to the tail vein, and then the pathological and diagnostic aspects of pulmonary AE were examined by magnetic resonance imaging (MRI). Histological primary, mature and degenerated AE lesions were observed 5, 18 and 50 weeks after injection, respectively. These lesions were discriminated as signal-void, hypointense and hyperintense regions in T1-weighted MRI (T1WI), respectively. The change in signal intensity in T1WI might reflect the content of proteinaceous fluid as a result of AE cyst degeneration. Western blot analysis of sera with antibodies of two epitopes (Em18 and Em16) of E. multilocularis provided evidence for AE infection in the early stage. T1WI in combination with Western blot analysis could possibility become definitive and early signs of hematogenous pulmonary AE infection.

Brain metastasis of alveolar echinococcosis in a hyperendemic focus of Echinococcus multilocularis infection

An unusual female case, with alveolar echinococcosis (AE) disseminated from the primary hepatic lesion to the brain by metastasis formation, was retrospectively identified during a community survey in Ningxia Hui Autonomous Region, northwest China in 2003. Among possible metastases of hepatic AE, locations to the brain are rare and usually fatal; and they have especially been assigned to concomitant immune suppression. An enhancing role of pregnancy, which may be suspected in this case, the favourable outcome after surgery and chemotherapy, and also a mental disability in a child following long-term intrauterine exposure to mebendazole, make the report particularly unique.

Comparison of contrast-enhanced power Doppler ultrasound (Levovist) and computed tomography in alveolar echinococcosis

BACKGROUND

To date, no study has compared unenhanced and contrast-enhanced (Levovist) power Doppler ultrasound with three-phase helical computed tomography (CT) for the analysis of the vascularization of hepatic lesions in patients who have alveolar echinococcosis.

METHODS

Fifteen patients (11 female and four male; average age, 45.8 years) with confirmed Echinococcus multilocularis infection underwent unenhanced and contrast-enhanced (Levovist) power Doppler ultrasound (2- to 5-MHz transducer head) and three-phase helical CT. The largest identified lesion in each patient was studied.

RESULTS

CT visualized vascularization peripheral or central to the largest echinococcal lesions in 11 of 15 patients. Vascularization in the area of the echinococcal lesions was not visualized by unenhanced or contrast-enhanced power Doppler ultrasound in any of the 15 patients studied.

CONCLUSION

Three-phase helical CT visualizes the vascularization associated with Echinococcus multilocularis lesions in the liver. Neither unenhanced nor contrast-enhanced ultrasound in power mode is suitable for this application.

Clinical considerations of primary hydatid disease of the pancreas

BACKGROUND

The pancreas is a rare primary location of hydatid disease. The purpose of our study is to gain more insight into this entity and to focus on the management and the diagnostic approach to the disease.

METHODS

The medical records of 5 patients with hydatid cysts of the pancreas were reviewed.

RESULTS

Four of the cysts were primary, while in 1 case a coexisting cyst was found in the liver. The body and tail of the pancreas were the most common locations. Clinical presentation varied according to the anatomic location of the cyst. Abdominal pain, discomfort and vomiting were the main clinical symptoms. One patient presented with obstructive jaundice, while another patient manifested a mild episode of anaphylactic shock. The indirect hemagglutination test was positive in 3 of 4 cases. A computed tomography scan successfully imaged all cysts and calcification of the cystic wall was found in 3 of 4 cases. All patients underwent surgical therapy. Hydatid cysts in the tail of the pancreas were successfully treated with distal pancreatectomy, while cysts in the body and head of pancreas were treated with proper evacuation, pericystectomy and omentoplasty. The postoperative course was uneventful in all patients except 1 who presented a pancreatic fistula and was re-operated. The mean length of hospitalization after surgery was 11-12 (range 10-13) days, except for the patient who needed to be re-operated. No evidence of cyst recurrence was observed during the follow-up period.

CONCLUSIONS

Hydatid cystic masses of the upper abdomen might also originate from the pancreas especially in endemic countries. Surgical excision of the entire cystic lesion remains the optimal treatment, offering hope for a complete cure.

Usefulness of PCR analysis for diagnosis of alveolar echinococcosis with unusual localizations: two case studies

The report presents two cases where diagnosis of alveolar echinococcosis was confirmed by Echinococcus multilocularis and Echinococcus granulosus PCR. The extrahepatic osseous involvement and the absence of initial hepatic involvement are unusual in both cases. Due to limitations of serological interpretation, PCR was useful to diagnose atypical echinococcosis.

[52-year-old patient with subcutaneous space-occupying lesion in immunosuppression]

We report the case of a 52-years-old male patient, who was diagnosed with subcutaneous alveolar echinococcosis 6 months after liver transplantation for HCV-related cirrhosis. Nether the explanted nor the transplantated liver revealed an echinococcus focus. Therefore a rare primary extrahepatic manifestation was likely. Interestingly, the echinococcal larvae had developed protoscolices. The development of mature tapeworms in human is a rarity, which could be related to the immunosuppressive therapy after liver transplantation. The patient was curatively treated by surgical removal of the subcutaneous tumor and a postoperative therapy with albendazole. Furthermore, HCV reinfection (genotype 2b) was successfully treated with interferone alpha 2b and ribavirine for 6 months.

Long-term benzimidazole treatment of alveolar echinococcosis with hematogenic subcutaneous and bone dissemination

We report a case of advanced alveolar echinococcosis (AE) that presented like a malignant tumor. It was diagnosed histologically from a subcutaneous nodule with skin inflammation on the right leg. Additionally, the patient showed bone metastases in the lower thoracic spine and the left third toe. This is the first case with proven hematogenic spread of AE to a subcutaneous site. The patient was treated with albendazole and remained stable for 6 years. When progression of AE occurred the therapy was changed to mebendazole, resulting in a stable condition for further 4 years.

Hydatid lung disease (echinococcosis/hydatidosis)

Two Echinococcus species may exhibit medical relevance as causative agents of pulmonary forms of echinococcosis. Most importantly, infections with Echinococcus granulosus result in "cystic hydatid disease" or "cystic echinococcosis," which affects the lungs in a considerable ratio of cases. Echinococcus multilocularis, which causes "alveolar echinococcosis," affects the lungs relatively rarely and then usually upon metastasizing from primary hepatic lesions. Cystic echinococcus and alveolar echinococcus differ pathologically and clinically so greatly that they are considered separately in this article, although alveolar echinococcus is covered minimally because of its minor importance regarding lung infections.