Embolization of Ruptured Hepatic Hydatid Cyst to Pulmonary Artery in an Elderly Patient Multidetector computed tomography findings

Pulmonary embolism due to hydatid disease is an unusual condition resulting from the rupture of a hydatic heart cyst or the opening of liver hydatidosis into the venous circulation. A 78-year old male patient complaining of dyspnea, cough and severe chest pain was admitted to our emergency department. A multidetector computed tomography of the chest revealed the presence of multiple nodules in both lungs especially in left and multiple hypodense filling defect in left main pulmonary artery and its branches. In addition, coronal reformatted multidetector computed tomography images also showed two hypodense cystic parenchymal masses on the left lobe of the liver with a cystic embolus in the right atrium. Pulmonary embolism should be kept in mind in patients who have hepatic hydatidosis if suddenly chest pain and dyspnoea occurs, especially in regions where hydatidosis is endemic.

Although more dominant in definite sheep-raising countries, worldwide travel has made hydatid liver disease much more prevalent in previously unaffected regions such as Northern Europe or North America.Hydatidosis is a parasitic infection produced by the larvae of Echinococcus granulosus.2][3] After ingestion, the embryos in the eggs release and migrate, most commonly to the liver and lungs; however, other organs can also become involved. 2,3The hydatid cyst of E. granulosus tends to develop in liver (50-70%), lungs (20-30%), or, less frequently, in other parts of the body, such as the brain, heart, and bones. 1,4Hydatid pulmonary embolism is an uncommon condition.It is usually seen in cardiac hydatidosis but it can be also due to inferior vena cava (IVC) or hepatic vein invasion in liver hydatidosis. 5We present multidedector computed tomography(MDCT) findings of a case of with liver hydatidosis causing massive pulmonary emboli.

Case Report
A 78-year-old male patient was admitted to the emergency department of Kahramanmaras Sutcu Imam University Hospital, Kahramanmaras, Turkey, complaining of dyspnoea, cough and severe chest pain.The patient had undergone coronary artery bypass grafting 10 years before.On admission, the patient was dyspneic and mildly cyanotic.On examination, the respiration rate was 36 breaths/minute and chest auscultation revealed crackles in his lower left pulmonary fields.His blood pressure (BP) was 130/80 mmHg.The pulse rate was 96 beats/minute.The electrocardiogram was normal, there was no leg oedema, and a laboratory evaluation was within normal limits.The patient had no symptoms suggestive of an anaphylactic reaction.
An MDCT pulmonary angiography was performed on suspicion of a pulmonary embolism.The MDCT of the chest with intravenous contrast administration showed multiple cysts in both lungs, with a predominance in the lower left lung [Figure 1], and a hypodense mass located in the left main pulmonary artery which was consistent with an intra-arterial hydatid cyst [Figure 2].In addition, coronal reformatted MDCT images also showed two hypodense cystic parenchymal masses on the left lobe of the liver and a cystic embolus in the right atrium [Figure 3].The patient's clinical history and imaging findings, and the prevalence of hydatid cysts in Turkey led to the diagnosis of a pulmonary embolism complicating a liver hydatid cyst.The patient refused surgical intervention and so was treated with a 30-day course of albendazole (Andazol®) 10 mg/kg/day in two divided oral doses, and cetirizine hydrochloride (Zyrtec®), oral 10 mg tablet, once a day.After several days, the patient's dyspnea and chest pain resolved with medical treatment and was discharged with his consent.

Discussion
The growth of hydatid cysts is usually slow and asymptomatic, and clinical manifestations are caused by compression of the involved organs.Additionally, if hydatid cysts are not detected in time, the cyst may become life-threatening and rupture. 6Intrabiliary rupture is the most common and life-threatening complication but intracaval rupture of hydatid disease of the liver is a rare complication.Pulmonary artery embolism due to hydatid cyst is an extremely rare entity.9][10] To the best of our knowledge, this is the first case in the literature where a ruptured liver echinococcal cyst resulted in pulmonary embolus in an elderly patient.In other studies, all patients were  Fuat Ozkan, Yakup Yesilkaya, Mahmut Tokur, Nuri Ozcan and Mehmet Fatih Inci Case Report | 167 dissemination of the disease, anaphylactic shock, embolism, and pseudoaneurysm formation. 3he degree of the degenerative changes in the arterial wall, proximal or distal localisations of the pulmonary artery occlusion and irreversible parenchymal changes are factors influencing the selection of the operative procedure. 3,4Some patients who refuse surgery should be treated with albendazole due to the disseminated nature of the hydatidosis. 4,13

Conclusion
A ruptured liver echinococcal cyst resulting in pulmonary embolus in an elderly patient is extremely rare.Pulmonary hydatid cyst emboli should always be one of the differential diagnoses of the hypodense and/or cystic intr-arterial pulmonary mass in a patient with hepatic hydatid cyst adjacent to the IVC or hepatic veins.younger than our patient.Being an elderly patient the possibility of a malignant disorder had to be excluded. 11erology, laboratory studies, and skin tests are useful in the diagnosis of hydatid diseases but they lack prognostic value in the determination of intravenous rupture of the hydatid cyst. 12The diagnosis of a hydatid pulmonary embolism is more effectively made through clinical and radiological findings. 1n enhanced CT, the intra-arterial cyst shows the typical hypodense appearance. 1 Coronal reformatted imaging can be a helpful diagnostic method in identifying the origin of the pulmonary hydatid emboli by showing the involvement in the IVC.Specifically, MDCT, which is non-invasive and easily available, is a very useful imaging modality for hydatidosis in the liver or other organs.Clinically, our case was not considered to be thromboembolic disease.Intra-arterial hypodense masses did not show contrast enhancement and that finding was interpreted as not in favour of an intra-arterial tumour.
Surgical intervention is the primary treatment for pulmonary artery hydatid embolus.Embolectomy and/or enucleation are often the preferred surgical options. 13However, rupture of the artery and/or the cyst during surgical intervention may cause

Figure 1 :
Figure 1: Multidedector computed tomography scan showing irregular, defined patchy lesions (black arrow in right, white arrows in left) in bilateral lung paranchima, especially in the left on lung window.

Figure 2 :
Figure 2: Multidedector computed tomography angiography shows hypodense masses located in the left main pulmonary artery (white arrow) and in the left distal pulmonary artery to the segmentary branches of the upper lobe.