CT imaging features and diagnostic algorithm for hepatic cystic echinococcosis

To systematically analyze CT imaging features of hepatic cystic echinococcosis (CE), explore radiological-pathological correlations, and develop a diagnostic algorithm for accurate disease classification. This retrospective study included 48 pathologically confirmed cases of hepatic CE from two medical centers. CT imaging features were analyzed by two experienced radiologists, evaluating lesion characteristics including location, morphology, wall features, and calcification patterns. Imaging findings were correlated with pathological results. A diagnostic algorithm was developed and validated, with inter-observer agreement assessed using Fleiss kappa coefficient. Seven distinct CT imaging patterns were identified, corresponding to different pathological stages: unilocular cystic (25.0%), multivesicular (8.3%), collapsed inner wall (10.4%), partially solidified (10.4%), solidified (16.7%), and calcified (25.0%) types, with complicated cases (4.2%) showing additional features. The proposed diagnostic algorithm achieved 94.0% accuracy (451/480 classifications) in validation testing by ten junior radiologists, with excellent inter-observer agreement (quadratic-weighted Fleiss kappa coefficient = 0.740 [95% CI 0.577-0.902], Gwet's AC2 coefficient = 0.768). Primary diagnostic challenges involved differentiating between CE2 and CE3b lesions, and between CE3b and CE4 lesions. This study explores the correlation between CT imaging patterns and pathological stages of hepatic CE, proposing a validated diagnostic algorithm. The findings provide valuable insights for CE classification, particularly in regions where the disease is emerging or underrecognized.

Dedifferentiated liposarcoma with extensive cystic change causing significant diagnostic challenges: report of two cases and review of the literature

BACKGROUND

Retroperitoneal dedifferentiated liposarcoma is a rare, aggressive malignancy, characterized by high rates of recurrences and the potential for metastasis. On imaging, these tumors typically present as a solid mass with lipomatous and non-lipomatous components. Cystic changes of dedifferentiated liposarcomas is exceedingly rare and might pose significant diagnostic challenges, with only a few cases reported in the literature. REPORT OF 2 CASES: We here present two cases of retroperitoneal dedifferentiated liposarcoma with a rare cystic presentation in two female patients aged 51 and 62 years. Imaging revealed large perinephric cystic masses measuring up to 13.0 cm and 16.1 cm, respectively, with calcifications of the cyst wall observed in the second case. Differential diagnoses included cystic echinococcosis, mesenchymal neoplasms, and benign cystic lesions (e.g. endometrial cyst). Both patients underwent upfront compartmental en-bloc surgical resection of the tumor mass and the kidney after multidisciplinary tumor board (MDT) discussion. Macroscopically, the tumors were adherent to but sharply demarcated from the kidney. Histological examination of the first case revealed a small component of well-differentiated liposarcoma (WDLPS) adjacent to a large non-lipogenic sarcoma with a prominent whirling pattern, compatible with dedifferentiation. The second case demonstrated a spindle cell neoplasm with prominent osteosarcomatous heterologous differentiation. MDM2 amplification was confirmed in both cases by molecular testing. No long-term follow-up data is available for either patient.

CONCLUSION

In conclusion, these cases highlight the importance of recognizing unusual and extensive cystic changes of dedifferentiated liposarcoma, which can complicate the diagnostic work-up.

Hydatid disease: imaging, treatment, and beyond

Hydatidosis is an endemic parasitic disease that can occur in almost any part of the body. It presents in two different forms according to the type of tapeworm: Echinococcus granulosus (hydatid disease [HD]) and Echinococcus multilocularis (alveolar HD). Radiological imaging can reveal the type of cyst, disease activity and progression, and complications, with features depending on the HD stage, the organ involved, and complications. Radiological imaging is also used to plan treatment strategies and evaluate patients at follow-up. Here, we review the morphologies of different HD presentations and their radiological features, the diagnostic findings that suggest possible HD in rare sites, and the potential complications of HD. We also discuss the role of radiology in hydatidosis diagnosis and treatment.

Imaging features and management of focal liver lesions

Notably, the number of incidentally detected focal liver lesions (FLLs) has increased dramatically in recent years due to the increased use of radiological imaging. The diagnosis of FLLs can be made through a well-documented medical history, physical examination, laboratory tests, and appropriate imaging methods. Although benign FLLs are more common than malignant ones in adults, even in patients with primary malignancy, accurate diagnosis of incidental FLLs is of utmost clinical significance. In clinical practice, FLLs are frequently evaluated non-invasively using ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI). Although US is a cost-effective and widely used imaging method, its diagnostic specificity and sensitivity for FLL characterization are limited. FLLs are primarily characterized by obtaining enhancement patterns through dynamic contrast-enhanced CT and MRI. MRI is a problem-solving method with high specificity and sensitivity, commonly used for the evaluation of FLLs that cannot be characterized by US or CT. Recent technical advancements in MRI, along with the use of hepatobiliary-specific MRI contrast agents, have significantly improved the success of FLL characterization and reduced unnecessary biopsies. The American College of Radiology (ACR) appropriateness criteria are evidence-based recommendations intended to assist clinicians in selecting the optimal imaging or treatment option for their patients. ACR Appropriateness Criteria Liver Lesion-Initial Characterization guideline provides recommendations for the imaging methods that should be used for the characterization of incidentally detected FLLs in various clinical scenarios. The American College of Gastroenterology (ACG) Clinical Guideline offers evidence-based recommendations for both the diagnosis and management of FLL. American Association for the Study of Liver Diseases (AASLD) Practice Guidance provides an approach to the diagnosis and management of patients with hepatocellular carcinoma. In this article, FLLs are reviewed with a comprehensive analysis of ACR Appropriateness Criteria, ACG Clinical Guideline, AASLD Practice Guidance, and current medical literature from peer-reviewed journals. The article includes a discussion of imaging methods used for the assessment of FLL, current recommended imaging techniques, innovations in liver imaging, contrast agents, imaging features of common nonmetastatic benign and malignant FLL, as well as current management recommendations.

Epicardial Space: Comprehensive Anatomy and Spectrum of Disease

The epicardial space (ES) is the anatomic region located between the myocardium and the pericardium. This space includes the visceral pericardium and the epicardial fat that contains the epicardial coronary arteries, cardiac veins, lymphatic channels, and nerves. The epicardial fat represents the main component of the ES. This fat deposit has been a focus of research in recent years owing to its properties and relationship with coronary gossypiboma plaque and atrial fibrillation. Although this region is sometimes forgotten, a broad spectrum of lesions can be found in the ES and can be divided into neoplastic and nonneoplastic categories. Epicardial neoplastic lesions include lipoma, paraganglioma, metastases, angiosarcoma, and lymphoma. Epicardial nonneoplastic lesions encompass inflammatory infiltrative disorders, such as immunoglobulin G4-related disease and Erdheim-Chester disease, along with hydatidosis, abscesses, coronary abnormalities, pseudoaneurysms, hematoma, lipomatosis, and gossypiboma. Initial imaging of epicardial lesions may be performed with echocardiography, but CT and cardiac MRI are the best imaging modalities to help characterize epicardial lesions. Due to the nonspecific onset of signs and symptoms, the clinical history of a patient can play a crucial role in the diagnosis. A history of malignancy, multisystem diseases, prior trauma, myocardial infarction, or cardiac surgery can help narrow the differential diagnosis. The diagnostic approach to epicardial lesions should be made on the basis of the specific location, characteristic imaging features, and clinical background. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

Primary seronegative intermuscular hydatidosis in a child, an infection that should be approached like a tumor: a case report and review of the literature

INTRODUCTION

Intermuscular hydatid cyst is one of the rarest types of hydatid cyst, and as far as we know, only nine cases were reported in the literature before this study.

CASE PRESENTATION

We present a 10-year-old Iranian child with an intermuscular cystic mass in the medial-distal thigh. Despite the typical imaging findings, the patient's serological and hematological tests were negative for hydatid cyst. The cyst underwent wide excision accompanied by neoadjuvant and adjuvant chemotherapy with Albendazole. No evidence of recurrence was detected during the one-year follow-up.

CONCLUSION

Hydatid cysts should always be considered in the differential diagnosis of soft tissue cystic masses in endemic areas, and aspiration or drainage should be avoided as much as possible, even when serological tests are negative and imaging is non-diagnostic. In cases where the diagnosis of a hydatid cyst has been confirmed before the surgery, it is recommended to approach the cyst, like a tumor with chemotherapy using Albendazole both before and after wide cyst excision.

Concurrent Abdominal and Mediastinal Hydatid Cystic Disease: A Rare Case

Hydatid disease in humans is caused by accidental ingestion of Echinococcus in its larval form. It mostly affects the liver and lungs, but rarely the mediastinum and other areas as well. The diagnosis is mostly confirmed intraoperatively in cases of mediastinal disease. The mainstay of treatment in such cases is surgery. This is a case report of a rare finding of hydatid disease in mediastinum along with the abdomen and its surgical management.

Primary intramuscular thigh hydatid cyst: A case report

INTRODUCTION AND IMPORTANCE

Hydatid cyst is a parasitic infection caused by Echinococcus granulosis. It mostly involves the liver and lungs; however, muscle involvement is an uncommon event. The diagnosis of such cystic masses is still a challenge due to the presence of more common pathological conditions in soft tissue. Imaging is useful and can identify a definitive diagnosis.

CASE PRESENTATION

We present a case of a 32-year-old woman with history of close contact with dogs and cats, who complained of an isolated swelling in the right upper thigh growing gradually over a period of 3 years. Ultrasound reported intramuscular hydatid cyst in the right thigh. Hydatid cyst was completely excised. The outcome was good, with no recurrence in one year.

CLINICAL DISCUSSION

Ultrasonography is an excellent and cost-effective imaging modality with a high negative predictive value in the evaluation of palpable superficial soft-tissue masses and hydatid cysts.

CONCLUSION

Isolated intramuscular hydatid cyst is rarely reported, even in endemic areas of the disease, so the diagnosis should be considered in any cystic masses of soft tissue, particularly in subjects from high-endemic zones. Although the treatment of choice in such cases is surgical excision but prevention is more favorable to fight against hydatid disease.

Unravelling Peritoneal Carcinomatosis Using Cross-Sectional Imaging Modalities

Peritoneal carcinomatosis (PC) refers to malignant epithelial cells that spread to the peritoneum, principally from abdominal malignancies. Until recently, PC prognosis has been considered ill-fated, with palliative therapies serving as the only treatment option. New locoregional treatments are changing the outcome of PC, and imaging modalities have a critical role in early diagnosis and disease staging, determining treatment decision making strategies. The aim of this review is to provide a practical approach for detecting and characterizing peritoneal deposits in cross-sectional imaging modalities, taking into account their appearances, including the secondary complications, the anatomical characteristics of the peritoneal cavity, together with the differential diagnosis with other benign and malignant peritoneal conditions. Among the cross-sectional imaging modalities, computed tomography (CT) is widely available and fast; however, magnetic resonance (MR) performs better in terms of sensitivity (92% vs. 68%), due to its higher contrast resolution. The appearance of peritoneal deposits on CT and MR mainly depends on the primary tumour histology; in case of unknown primary tumour (3-5% of cases), their behaviour at imaging may provide insights into the tumour origin. The timepoint of tumour evolution, previous or ongoing treatments, and the peritoneal spaces in which they occur also play an important role in determining the appearance of peritoneal deposits. Thus, knowledge of peritoneal anatomy and fluid circulation is essential in the detection and characterisation of peritoneal deposits. Several benign and malignant conditions show similar imaging features that overlap those of PC, making differential diagnosis challenging. Knowledge of peritoneal anatomy and primary tumour histology is crucial, but one must also consider clinical history, laboratory findings, and previous imaging examinations to achieve a correct diagnosis. In conclusion, to correctly diagnose PC in cross-sectional imaging modalities, knowledge of peritoneal anatomy and peritoneal fluid flow characteristics are mandatory. Peritoneal deposit features reflect the primary tumour characteristics, and this specificity may be helpful in its identification when it is unknown. Moreover, several benign and malignant peritoneal conditions may mimic PC, which need to be considered even in oncologic patients.

Primary cervical hydatid cyst: A rare case report

INTRODUCTION AND IMPORTANCE

Hydatid cyst is a zoonotic parasitic disease caused by Echinococcus granulosis. Occurrence in the head and neck is quite uncommon even in endemic areas. The diagnosis of an isolated cystic neck mass is still a challenge due to the presence of similar congenital cystic lesions and benign tumors in the neck. Imaging is useful, but sometimes they cannot identify a definitive diagnosis. The treatment of choice is exclusively surgical excision, combined with chemotherapy. Histopathology confirms the definitive diagnosis.

CASE PRESENTATION

We present a case of an 8-year-old boy with no history of surgery or trauma, who complained of an isolated left posterior neck mass since one year. All radiological items lead to suspect a cystic lymphangioma. Excisional biopsy under general anesthesia was done. The cystic mass was totally resected and the diagnosis was further confirmed by histopathology.

CLINICAL DISCUSSION

Cervical hydatid cyst is mostly a misdiagnosed condition, majority of hydatid cyst cases are asymptomatic and vary on the basis of their locations. The differential diagnosis includes cystic lymphangioma, branchial cleft cyst, bronchogenic, thoracic duct, esophageal duplication cysts, pseudocysts and benign tumors.

CONCLUSION

Isolated cervical hydatid cyst is rarely reported yet, it must be considered in any cases of cystic cervical mass, particularly in endemic areas. Imaging modalities are sensitive in diagnosing cystic lesions, yet sometimes they cannot identify the exact etiology of the lesion. Furthermore, Prevention of hydatid disease is more favorable than surgical excision.

Precordial pain induced by the isolated cardiac hydatid cyst in interventricular septum: a case report

BACKGROUND

Human hydatid disease occurs after infection with Echinococcus granulosus, mainly involves liver and lung, while hydatid involves heart is infrequent. A great majority of hydatid diseases could be asymptomatic, and incidentally found through examination. Here, we reported a woman who suffered an isolated cardiac hydatid cyst located at the interventricular septum.

CASE PRESENTATION

A 48-year-old woman presented intermittent chest pain was admitted to the hospital. Imaging examination revealed a cyst located at the interventricular septum near the right ventricular apex. Considering medical history, radiological findings and serological results, cardiac hydatid disease was suspected. The cyst was successfully removed, while pathological biopsy confirmed the diagnosis of infection of Echinococcus granulosus. Postoperative course was uneventful, the patient was discharged from hospital without complications.

CONCLUSION

For symptomatic cardiac hydatid cyst, surgical resection is necessary to avoid progression of disease. During surgical procedure, appropriate methods to reduce the potential risk of hydatid cyst metastasis are essential. Besides surgery, combined with regular drug therapy is an effective strategy to prevent reappearance.

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.

Peritoneal disease: key imaging findings that help in the differential diagnosis

The peritoneum is a unique serosal membrane, which can be the site of primary tumors and, more commonly, secondary pathologic processes. Peritoneal carcinomatosis is the most common malignant condition to affect the peritoneal cavity, and the radiologist plays an important role in making the diagnosis and assessing the extent of disease, especially in sites that may hinder surgery. In this review, we address the role of the radiologist in the setting of peritoneal pathology, focusing on peritoneal carcinomatosis as this is the predominant malignant process, followed by revising typical imaging findings that can guide the differential diagnosis.We review the most frequent primary and secondary peritoneal tumor and tumor-like lesions, proposing a systemic approach based on clinical history and morphological appearance, namely distinguishing predominantly cystic from solid lesions, both solitary and multiple.

Incurable and refractory spinal cystic echinococcosis: A case report

BACKGROUND

Although the incidence and cure rate of spinal hydatidosis are low, the recurrence rate of spinal hydatidosis is high, and the prognosis of spinal hydatidosis is poor. Therefore, we report a typical case of refractory spinal hydatidosis to increase spine surgeons’ awareness of the disease and reduce misdiagnosis and recurrence.

CASE SUMMARY

A 48-year-old man presented with back pain, significant weight loss, and paralysis of both lower limbs. The patient was misdiagnosed with spinal tuberculosis in an outside hospital. However, spinal magnetic resonance imaging (MRI) showed hyperintense cystic components on T2-weighted images and hypointensity on T1-weighted images. A lobulated, multiocular, honeycomb-appearance, septated cystic mass protruding intraspinally and compressing the spinal cord at segments T8–T9 was present. Paravertebral polycystic lobular lesions presented as a “bunch of grapes”. The ELISA test result for Echinococcus granulosus was positive. Then, a diagnosis of spinal hydatidosis and lung hydatid disease was made, and the patient underwent left transthoracic approach lobectomy, paravertebral lesion debridement, and subtotal vertebrectomy with vertebral body replacement of segments T8 and T9 by a mesh cage. The patient also underwent albendazole chemotherapy before and after surgery. One year after stopping the drug therapy, the patient developed recurrent T5 vertebral lesions and underwent a second subtotal vertebrectomy surgery. The patient is currently in good condition and is receiving long-term medication and follow-up.

CONCLUSION

The MRI feature of a “bunch of grapes” is a typical imaging indication of spinal hydatidosis. Subtotal vertebrectomy is a risk factor for postoperative recurrence. Total spondylectomy makes it possible to cure spinal hydatidosis, but antiparasitic drug therapy is also an important supplementary therapy to multimodal therapy. It is preferable for patients with spinal hydatidosis to receive life-long antiparasitic medication therapy and follow-up.

A rare phenotype of breast hydatid cyst causing misdiagnosis and unnecessary intervention: a case report

Hydatid cyst (cystic echinococcosis) is a chronic parasitic infection by the larval stage of the cestode that is called Echinococcus granulosus (E. granulosus) resulting in the development of cystic lesions in animals and humans. In this report, we describe a rare phenotype of hydatid cyst in the breast of a 23-year-old female presented with breast mass in the left upper outer quadrant for 3 months with palpable left axillary lymph nodes. Both US and mammography provided a picture of complex suspicious cystosolid lesion with amorphous micro-calcification (BIRAD-4A). Surgical consultation was performed and Tru-Cut biopsy was recommended. Histopathology results revealed multiple viable protoscolices of E. granulosus and suggested the final diagnosis of breast hydatid cyst. The patient returned with ruptured and infected hydatid cyst of the breast and started treatment with Albendazole 400 mg twice daily in addition to antibiotics. Following-up after two months of Albendazole treatment showed a dramatic shrinkage in the size of the cystic lesion. In conclusion, hydatid cyst should be considered as a differential diagnosis of any cystic or cystosolid lesion in the breast and any organ in the body from head to toe apart from the hair and nails. Radiologists should be aware to the benign lesions that may mimic breast cancer to avoid misdiagnosis and unnecessary invasive procedures and consequent complications.

Hydatid disease as a rare cause of neck swelling: Two cases report

INTRODUCTION

Despite the fact that hydatid disease is endemic in some countries, its cervical location remains very rare.

PRESENTATION OF CASE

We report two cases of primary cervical hydatid disease in two children from rural areas. The imaging was not specific, since the location is rare; the diagnosis was only confirmed after surgery.

DISCUSSION

Hydatid cyst is a rare pathology. Thus clinical presentation, radiological examinations, fine needle aspiration and serology can be useful to suspect the diagnosis.

CONCLUSION

Hydatid disease should be considered when dealing with slow-growing renitent neck swelling in endemic countries.

Renal hydatidosis masquerading as xanthogranulomatous pyelonephritis: a new case report

Human hydatid disease is still endemic in pastoral and rangeland areas, with temperate climate, mainly in the southern shore of the Mediterranean, particularly in the Maghreb countries. Renal localization is rare although it is the most frequent site of the urinary tract. Its clinical evolution remains silent for long time, and the diagnosis is often elusive for years. Renal hydatid cysts may pose a problem of differential diagnosis. Our case concerns a renal hydatidosis misdiagnosed as a xanthogranulomatous pyelonephritis, treated by total nephrectomy.

Computed tomography and magnetic resonance imaging of hydatid disease: A pictorial review of uncommon imaging presentations

Hydatid disease (HD), also known as echinococcal disease or echinococcosis, is a worldwide zoonosis with a wide geographic distribution. It can be found in almost all parts of the body and usually remains silent for a long period of time. Clinical history can be varied based on the location, size, host immune response, and complications.

The most common imaging modalities used for diagnosis and further evaluations of HD are ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI). Although conventional radiography may be the first used tool, rarely can lead to a definite judgment. Clinical indications and cyst location may alter the choice of imaging. MRI and CT would be useful when the involved area is inaccessible for ultrasound or surgical treatment is required. CT is particularly valuable for osseous organ involvements and the presence of calcifications in the cyst and also demonstrates the size, number, and local complications. MRI can differentiate HD from neoplasms in cases with an unusual appearance on imaging. Moreover, it is preferable in biliary or neural involvements. Besides, more detailed images of MRI and CT could help to resolve the diagnostic uncertainty.

Imaging is the main stem for HD diagnosis. Brain, orbit, muscle, bone, and vascular structures are less commonly involved areas. Familiarity with typical clinical presentation, CT scan and MR imaging findings of HD in this sites facilitate the radiologic diagnosis and guiding appropriate treatment.

Identification of candidate biomarkers of liver hydatid disease via microarray profiling, bioinformatics analysis, and machine learning

Objectives

Liver echinococcosis is a severe zoonotic disease caused by Echinococcus (tapeworm) infection, which is epidemic in the Qinghai region of China. Here, we aimed to explore biomarkers and establish a predictive model for the diagnosis of liver echinococcosis.

Methods

Microarray profiling followed by Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis was performed in liver tissue from patients with liver hydatid disease and from healthy controls from the Qinghai region of China. A protein–protein interaction (PPI) network and random forest model were established to identify potential biomarkers and predict the occurrence of liver echinococcosis, respectively.

Results

Microarray profiling identified 1152 differentially expressed genes (DEGs), including 936 upregulated genes and 216 downregulated genes. Several previously unreported biological processes and signaling pathways were identified. The FCGR2B and CTLA4 proteins were identified by the PPI networks and random forest model. The random forest model based on FCGR2B and CTLA4 reliably predicted the occurrence of liver hydatid disease, with an area under the receiver operator characteristic curve of 0.921.

Conclusion

Our findings give new insight into gene expression in patients with liver echinococcosis from the Qinghai region of China, improving our understanding of hepatic hydatid disease.

Cystic Echinococcosis in Children: High Frequency of Multiple Organs Involved in the North of Iran

INTRODUCTION

Echinococcosis, as an important zoonotic infection, has a major worldwide distribution. Pediatric echinococcosis has still become health concerning issue in developing countries, particularly, in the Middle East and Iran. The aim of this study was to investigate the human echinococcosis in children in northern Iran.

METHODS

Patients admitted to the pediatric subspecialty hospital of Amir Kala, Babol, Iran, from 2011 to 2016 with a confirmed diagnosis of echinococcosis, were reviewed. Records of the patients, including demographic data, clinical manifestations of the disease, type of cysts, and other related factors, were collected.

RESULTS

Sixteen pediatric patients, twelve (75%) male, and four (25%) female were evaluated. All cases had cystic echinococcosis. The results showed that fever (75%) following vomiting, nausea, and coughing (44%) were the most common clinical manifestations. The most common localizations of cases were determined as liver (n=10, 62.5%) and lung (n=9, 56%). The frequency of the involvement of more than one organ was 31% (5 cases). The co-occurrence of liver and lung was seen in 2 (12.5%) cases, and in one case, the co-occurrence of the liver and spleen was reported. In one case, lung, liver and, the pelvis was involved, while in another case, liver, sub diaphragm and kidney involvement were observed.

CONCLUSION

Cystic echinococcosis should be kept in mind when a cystic lesion is encountered anywhere in the body, particularly, in patients lining in the endemic regions. Since cystic echinococcosis has a considerable economic impact in Iran, the implementation of a control program and the surveillance system are highly recommended to reduce the economic burden of this disease.

Benign Neoplasms, Mass-Like Infections, and Pseudotumors That Mimic Hepatic Malignancy at MRI

A variety of conditions may mimic hepatic malignancy at MRI. These include benign hepatic tumors and tumor-like entities such as focal nodular hyperplasia-like lesions, hepatocellular adenoma, hepatic infections, inflammatory pseudotumor, vascular entities, and in the cirrhotic liver, confluent fibrosis, and hypertrophic pseudomass. These conditions demonstrate MRI features that overlap with hepatic malignancy, and can be challenging for radiologists to diagnose accurately. In this review we discuss the MRI manifestations of various conditions that mimic hepatic malignancy, and highlight features that may allow distinction from malignancy. Level of Evidence 5 Technical Efficacy Stage 3.

Non-neoplastic conditions mimicking peritoneal carcinomatosis at CT imaging

The general appearance of peritoneal carcinomatosis at abdominal CT and other cross-sectional imaging modalities consists of varying amounts of peritoneal-based soft tissue implants (mass-forming or infiltrative), peritoneal fluid, and occasionally calcification. However, a wide variety of common and uncommon neoplastic and non-neoplastic conditions can closely mimic peritoneal carcinomatosis at imaging. Neoplastic mimics of peritoneal carcinomatosis include primary peritoneal and sub peritoneal tumors, as well as peritoneal lymphomatosis and sarcomatosis.Broad categories of non-neoplastic mimics of peritoneal carcinomatosis include tumor-like conditions, systemic processes, atypical infections, and fat-based conditions. For many entities, suggestive or specific patient information and/or CT imaging findings exist that may allow the radiologist to narrow the differential diagnosis. In this article, we review the salient clinical and cross-sectional imaging features of non-neoplastic mimics of peritoneal carcinomatosis and malignancy, with emphasis on the CT findings and the additional clues that may suggest the correct benign diagnosis.

Parasitic infections of the spine: case series and review of the literature

OBJECTIVEAlthough parasitic infections are endemic to parts of the developing world and are more common in areas with developing economies and poor sanitary conditions, rare cases may occur in developed regions of the world.METHODSArticles eligible for the authors' literature review were initially searched using PubMed with the phrases "parasitic infections" and "spine." After the authors developed a list of parasites associated with spinal cord infections from the initial search, they expanded it to include individual diagnoses, using search terms including "neurocysticercosis," "schistosomiasis," "echinococcosis," and "toxoplasmosis."RESULTSTwo recent cases of parasitic spinal infections from the authors' institution are included.CONCLUSIONSKey findings on imaging modalities, laboratory studies suggestive of parasitic infection, and most importantly a thorough patient history are required to correctly diagnose parasitic spinal infections.

Ventricular Tachycardia and the Cystic Heart: A Case Report

BACKGROUND

Hydatid cysts are caused by Echinococcus granulosus infection, and hydatidosis is recognized as a re-emerging zoonotic disease globally. While the liver is the most commonly affected organ, other organs can also be affected, including the heart. Because of the low sensitivity and specificity of serologic diagnostic tests, ultrasound and echocardiography are increasingly used to make the diagnosis of cardiac hydatid cyst.

CASE REPORT

We report the case of a cardiac hydatid cyst, detected by point-of-care ultrasound (POCUS), in a 79-year-old woman who presented with shortness of breath and was in ventricular tachycardia. The diagnosis was further confirmed with a computed tomography scan. Although cases of alveolar and liver hydatid cysts are seen, this is the first case of a cardiac hydatid cyst in Bhutan. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: This case illustrates the importance of POCUS in reaching a diagnosis, particularly in resource-poor areas where other sophisticated diagnostic tools are not easily available. A cardiac hydatid cyst must be in the differential for structural causes of dysrhythmias. This is especially so because treatment of unstable dysrhythmias in the acute setting of an emergency department has to be modified from the usual algorithm in the presence of a cardiac hydatid cyst, due to the potentially fatal risk of cyst rupture and anaphylaxis.

Case 269: Sacroiliac Joint Hydatid Disease

HistoryA 20-year old woman living in Turkey presented with a 3-month history of lower back pain. She had no medical history of note and was taking no medications. Complete blood count, C-reactive protein level, sedimentation rate, and creatinine, alanine aminotransferase, and aspartate aminotransferase levels were within normal limits. Anteroposterior pelvic radiography and unenhanced pelvic CT were performed to rule out sacroiliitis. The imaging findings were abnormal, and the patient underwent contrast-enhanced sacroiliac MRI. A few days later, she underwent contrast-enhanced (100 mL iohexol, Omnipaque; GE Healthcare, Cork, Ireland) abdominal CT because of right upper quadrant pain.

Staged management of a giant cardiac hydatid cyst: a case report

BACKGROUND

We report on a 21-year-old patient with a giant symptomatic hydatid cyst of the interventricular septum, to whom a staged management approach was employed. Induction medical therapy led to a reduction in the size of the cyst, which was then completely removed via surgical excision.

CASE PRESENTATION

A 21-year-old male Caucasian, with main complaints of fatigue and palpitations, was referred to our Centre due to a cystic formation in his left ventricle. The workup consisted of transthoracic echocardiography and cardiac magnetic resonance, which revealed a huge hydatid cyst in an active stage of disease, occupying the basal and mid part of the interventricular septum. Due to the size of the lesion and lack of viable myocardium in the affected area, the patient was declared inoperable and medical therapy was initiated. Serial echocardiography revealed a significant reduction in the size of the lesion and degradation to transitional and inactive stage, after which successful surgical excision of the cyst was performed. In the course of the medical treatment, the patient experienced sustained ventricular tachycardia causing loss of consciousness, which did not reoccur after surgical excision.

CONCLUSION

Medical therapy can result in the degradation of a giant heart hydatid cyst, enabling surgical excision. Heart hydatid cyst can lead to potentially lethal arrhythmia irrespective of its size and stage, which does not reoccur after successful surgical excision.

Hydatid disease: MR imaging of calvarium and superior sagittal sinus involvement

Extra-axial hydatid disease (HD) is rare and may create a diagnostic challenge. Herein, we report an extremely rare case of calvarial HD with superior sagittal sinus invasion and an extension to the scalp with unusual magnetic resonance imaging findings simulating osteomyelitis and abscess. Recognition of detached endocystic membranes was the most important clue for the correct diagnosis. HD should be included in the differential diagnosis for a patient having a destructive skull lesion with peripheral enhancing extra-axial soft tissue component. Preoperative correct imaging diagnosis is crucial to improving patient management.

Surgery of the pancreatic cystic echinococcosis: systematic review

The prevalence of pancreatic cystic echinococcosis (PCE) in the world is low ranging between 0.2% and 0.6%. The diagnosis of PCE is easy when it is associated to other location such as liver, it became difficult when PCE was isolated simulating other diagnosis such as pseudocyst, a choledochal cyst, serous or mucinous cystadenoma and cystadenocarcinoma. This systematic review aimed to provide evidence-based answer to the following questions: (I) what are the efficient tools to affirm the diagnosis of isolated PCE and (II) what are the best therapeutic strategy for the PCE? An electronic search was performed by two authors (W Dougaz, I Bouasker). Medline, Scopus, Embase, Web of Science, Google Scholar and Cochrane collaboration were consulted. The keywords used were "cyst", "echinococcosis", "hydatid cyst" and "pancreas". All abstracts were analyzed followed by extraction of the full text by the same two authors (W Dougaz, I Bouasker), all divergences were resolved by discussion with C Dziri. Recommendations were based on Oxford's classification: (I) what are the efficient tools to affirm the diagnosis of PCE? -ultrasound remains the cornerstone of diagnosis. Magnetic resonance imaging (MRI) reproduces the ultrasound defined features of CE better than computed tomography (CT). MRI with heavily T2-weighted series is preferable to CT. Pancreatic duct MRI should be promising to identify a fistula between PCE and pancreatic duct (level of evidence 3-recommendation B); (II) what are the best therapeutic strategy for the PCE? -surgery is the main treatment of PCE. Open approach is validated. The decision depends of the location of PCE: head versus body and/or tail of the pancreas (level of evidence 5-recommendation D): for the head of the pancreas, the tendency is toward conservative surgery. For body and/or tail of the pancreas, the tendency is toward radical surgery. Medical treatment (albendazole) should be prescribed 1 week before surgery and 2 months during postoperative period (level II evidence and grade C recommendation).