Giant isolated hydatid lung cyst: two case reports

Epidemiology of Echinococcus granulosus sensu lato in the Greater Horn of Africa: A systematic review

BACKGROUND

Cystic echinococcosis (CE) is a neglected zoonotic disease that is caused by Echinococcus granulosus sensu lato (s.l.), the life cycle of which involves multiple hosts. We conducted a systematic review (SR) on E. granulosus s.l. in the Greater Horn of Africa (GHA), to provide a picture of its recent epidemiology across all hosts.

METHODS

For this SR, conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement, five electronic databases, as well experts in the region were consulted to retrieve records published between 2000 and 2022, reporting the presence of E. granulosus s.l. infections in any natural host in the GHA (Djibouti, Eritrea, Ethiopia, Kenya, Sudan, Somalia, South Sudan, Tanzania and Uganda).

PRINCIPAL FINDINGS

A total of 247 records were retained, describing the presence of E. granulosus s.l. throughout the GHA, except for Djibouti. Only few population surveys on human CE were conducted in the area, with the prevalence ranging between 0.3 and 11.3%. In animals, the reported prevalence ranged up to 61.6% in camels, 88.4% in cattle; 65.2% in goats, 9.9% in pigs, 67.8% in sheep and 94.5% in dogs. In addition, E. granulosus s.l. was also reported in wildlife. A total of five species were reported in the different hosts, namely E. granulosus sensu stricto (G1, G3, GOmo), E. canadensis (G6/7), E. ortleppi (G5), E. felidis, and E. equinus (G4).

CONCLUSIONS

We confirm that E. granulosus s.l. is prevalent throughout the GHA. Nevertheless, despite our efforts to screen grey literature, an accurate assessment of the epidemiology in GHA remains challenging, due to the lack of combined host, in-depth risk factor and behavioural studies, as well as the wide diversity in subpopulations studied and diagnostic tools used. Interdisciplinary and transboundary partnerships would be essential for the design of effective control strategies, tuned to the GHA setting.

The Neoplasms Mimicker: A Pictorial Review of Hydatid Disease

Hydatid cyst is a common name for the larval stage of a tapeworm species of the genus Echinococcus granulosus, which is transmitted from animals to humans via the fecal–oral route. Hydatid cysts predominantly affect the liver (75%), followed by the lung (15%), and they can affect many organs in the human body. Medical imaging modalities are the keystone for the diagnosis of hydatid cysts with high sensitivity and specificity. Ultrasound imaging with high resolution is the first choice for diagnosis, differential diagnosis, staging, establishing a role in interventional management, and follow-up, and it can differentiate Type I hydatid cysts from simple liver cysts. Unenhanced computed tomography (CT) is indicated where or when an ultrasound is unsatisfactory, such as with chest or brain hydatid cysts, when detecting calcification, and in obese patients. Magnetic resonance imaging (MRI) is superior for demonstrating cyst wall defects, biliary communication, neural involvement, and differentiating hydatid cysts from simple cysts using diffusion-weighted imaging (DWI) sequences. According to the phase of growth, hydatid cysts occur in different sizes and shapes, which may mimic benign or malignant neoplasms and may create diagnostic challenges in some cases. Hydatid cysts can mimic simple cysts, choledochal cysts, Caroli’s disease, or mesenchymal hamartomas of the liver. They can mimic lung cystic lesions, mycetoma, blood clots, Rasmussen aneurysms, and even lung carcinomas. Differential diagnosis can be difficult for arachnoid cysts, porencephalic cysts, pyogenic abscesses, and even cystic tumors of the brain, and can create diagnostic dilemmas in the musculoskeletal system.

Ruptured pulmonary hydatid cyst presenting as hemoptysis in TB endemic country: A case report

Introduction

Hydatid disease is a major zoonotic disease. After the liver, the lungs are the common site of involvement. Clinical manifestations of the disease depend on the site and size of the cysts as well as the presence of complications. The majority of the cases remain asymptomatic. Complicated pulmonary cysts can present as chest pain, cough, shortness of breath, and hemoptysis. Sometimes, imaging is not sufficient for diagnosis and histopathological evaluation can provide the confirmatory diagnosis.

Case presentation

A 32-year-old female presented with the complaints of episodic hemoptysis for the duration of two years. Radiological imaging could not provide a confirmatory diagnosis. Bronchoscopy was planned further. An endobronchial biopsy was taken for histopathological evaluation after seeing the whitish membranous structure within the right middle lobe bronchus. Hence, the diagnosis of ruptured cystic pulmonary hydatidosis was made.

Clinical discussion

Echinococcus granulosus is the cause of cystic pulmonary hydatid disease which is transmitted through contamination by the infected definitive host, mostly dogs. Most cases remain asymptomatic for a long period. Hydatid disease has many clinical and radiological forms which should be recognized and included in the differential diagnosis of many pulmonary problems. Sometimes, imaging and serological studies may not confirm the diagnosis, histopathological evaluation may be required.

Conclusion

Uncomplicated hydatid cysts are most commonly diagnosed incidentally in the adult population. Complicated hydatid cyst can present with various clinical manifestations. Episodic hemoptysis is one of the manifestations in our case. Clinicians should be aware of the typical as well as atypical manifestations of pulmonary hydatid disease.

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Ruptured pulmonary hydatid cyst usually presents with anaphylactic reaction but hemoptysis alone can be a presentation.

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Imaging and histologic findings help in confirming the diagnosis.

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Preventive educational program and early identification with atypical features are vital to prevent potential complications.