Clinical History
A 45-year-old shepherd was admitted for thoracic pain and acute dyspnoea.
Transthoracic echocardiography and CT were performed revealing pericardial effusion and two cystic masses.
Imaging Findings
CT examination showed a thin-walled unilocular cyst adjacent to the right ventricle and another calcified ruptured cyst next to the left ventricle, accompanied by a pericardial effusion. The morphologic features and the history of contact with dogs led to the diagnosis of pericardial hydatid cysts. Emergency thoracic surgery was performed.
Discussion
Hydatidosis is a parasitic infection caused by Echinococcus granulosus. The incidence of cardiac envolvement is <2%, even in countries where it is endemic with the interventricular septum and left ventricular free wall being more affected.
Patients may remain asymptomatic or present nonspecific symptoms during many years. Prior history of hydatid disease associated to hypereosinophilia can lead to the diagnosis of hydatid cysts. Diagnosis is confirmed by imaging techniques [1].
Echocardiography is a reliable technique for the diagnosis of intracardiac masses, but in some cases the echoluscent and multiseptate nature of echinococcal cysts may be absent.
Therefore hydatid cysts, in endemic areas, should be included in the list of differential diagnosis of cardiac tumours [1].
Cardiac motion artefacts limit the CT evaluation of small cystic lesions localised in the myocardium. However, the increasing use of multidetector CT scanners have overcome this problem.
Indeed, a round, thin-walled, multiloculated mass is characteristic of a hydatid cyst. Septa and calcifications may occasionally coexist. However, identification of cardiac and pericardial hydatid cysts may be very difficult, particularly the small ones [2].
In the presented case, although there was no prior history of hydatid cyst, the imaging findings and the history of contact with dogs led to the diagnosis.
Although medical treatment (albendazole) has shown interesting results, surgery is still the treatment of choice [1, 2].
Pericardial hydatid cyst is a rare pathology, but in endemic areas a very high suspicion is justified in any cystic disease of pericardium. Once diagnosed, early surgical excision is required to prevent complications.
Differential Diagnosis List
Pericardial tamponade due to ruptured pericardial hydatid cysts
Cardiac tumours
Pericardial tumours
Final Diagnosis
Pericardial tamponade due to ruptured pericardial hydatid cysts
