Dec 26, 2008 - Primary mediastinal hydatid cyst causing a paralysis of the recurrent nerve. El Hassane Kabiri1 MD, Fouad Atoini1 MD, Meryem Kabiri2 MD.
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IJTCVS 2008; 24: 264–265
Primary mediastinal hydatid cyst causing a paralysis of the recurrent nerve El Hassane Kabiri1 MD, Fouad Atoini1 MD, Meryem Kabiri2 MD 1 Department of Thoracic Surgery, Mohamed V Military Teaching Hospital (Hôpital Militaire d’Instruction Mohamed V) Hay Riad 10100 Rabat, Morocco,2 Center for Clinical Trials and Epidemiological Studies (CRECET), Medical School University Mohammed V Souissi, Rabat, Morocco Abstract Hydatid cyst disease stills a health problem in Morocco. We describe a rare case of a mediastinal hydatid disease that developed in the left thoracic cavity, and associated with paralysis of the left recurrent laryngeal nerve. Paralysis of thoracic nerve (phrenic nerve, sympathetic ...) to the best of our knowledge, there is only one case report of paralysis of the left recurrent laryngeal nerve secondary to compressive effects from mediastinal hydatid cysts. (Ind J Thorac Cardiovasc Surg 2008; 24: 264-265) Key words: Hydatid disease, Bronchoscopy, Thoracotomy Introduction Hydatid cyst is a parasitosis caused by Echinococcus granulosis larvae. The liver and the lung were the most frequent localisation but the cysts can be found anywhere in the body. Mediastinal localisation is very rare, with possibility of compression of the neighbours organ and structures. Case report A 44-year-old man was admitted to our department with a 6 mouth long history of paralysis recurrent nerve; chest pain and cough. The physical examination was normal. The postero-anterior chest x-ray showed superior left mediastinal opacity. Laboratory findings and bronchoscopy were normal. Thoracic computed tomography (CT) revealed a left mediastinal cystic mass 37 x 44x70 mm in diameter (Fig. 1 A, B). This structure is located superior to the aortic arch and it lies to the left and in close relation to the origin of the left Address for correspondence: Dr. El Hassane Kabiri Immeuble 29 Appt 7 Résidence Mesk Ellil, Secteur 23 Riad 10100 Rabat, Morocco Tel: 00 (212) 61 81 85 45 Email: hassankabiri @yahoo.com © IJTCVS 097091342441208/29 CR Received - 05/05/08; Review Completed - 23/09/08; Accepted - 25/09/08.
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subclavian vein. Its superior extent lies at the cervical level. Serologic test (indirect hemaglutination, immunoelectrophoresis and Elisa) were negative. A left posterolateral thoracotomy was performed through the fifth intercostal space; the mass was located in the middle upper mediastinum, under the aortic cross. A needle ponction was done, that a fluid ‘like water’ after protecting the cyst with soaked sponges of scolicidal agent (H2O2), we then used a needle to aspirate fluid, followed by remove the germinative membrane (Fig. 2), and resection of the residual cavity. A part of the cystic wall was left in place being intimately sticked to the left subclavian artery, and evicted to the recurrent nerve. Histopathological exam of the resected material confirmed the diagnosis of hydatid cyst (sub total pericystectomy). The post-operative course was uneventful, and the patient was discharged at day +2 and he lived the hospital at day +4. Medical treatment, albendazol (15mg/kg/day) was given for 3 months. After 6 months an objective regression of the dysphonia was noted without recurrence Discussion Hydatid cyst can be located in all tissues, although mediastinal hydatid cyst has been rarely reported in the literature: less than 1% in the chest and less than 0.1% of the all body localisation1,2. In our department in a period of 6 years, 128 patients with thoracic hydatid cyst
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disease were treated surgically, only 2 cases had primary mediastinal hydatid cyst (1.5%). A mediastinal hydatidosis is usually primitive and isolated. The larvae would reach the region after passing through the hepatic and pulmonary filter. Probably via an arterial branch of the thoracic aorta or via lymphatic system. The diagnosis of mediastinal hydatid cyst is very difficult because there is clinical or radiological sign distinguishable from other mediastinal cystic mass, and the diagnosis can be obtained through the combined of epidemiological, clinical, radiological and laboratory investigation data.
Fig. 1. A: Horizontal image of CT showing a cystic mass 37 x 44x70 mm in diameter with calcifications, B: Coronal image of CT showing a cystic mass subaortic and extended along the subclavian artery. CT : Computed tomography
Symptoms are not specific depend on the size, location and compression of adjacent structures. Nervous signs were described like Pancost syndrome, phrenic paralysis, and spinal symptoms3,4. we think that our case is the second reported with paralysis of the recurrent nerve5. Chest x-ray, computed tomography scan, magnetic resonance imaging (MRI) facilitate diagnosis, the presence of calcification is very suspicious of the hydatid origin of the mediastinal cyst. The presence of calcifications is in contrast to pulmonary hydatidosis (because of the relationship to ventilation)1,2. Thoracic computed tomography is very useful and instructive to the surgeon to define the relationship of the lesion with adjacent structures. MRI is useful in the posterior localisation (spinal involvement, case with neurologic signs). Serological tests are often negative when the cyst is intact and uncomplicated. Fine needle Computed tomography guided aspiration is still considered dangerous with a risk of rupture, dissemination and anaphylactic shock2. The only treatment of mediastinal hydatid cyst is surgical, in order to relieve compression over neurologic structures, and to evicted the rupture in the pleural cavity6,7. or in the vascular cardiac cavity2. The medical treatment is proposed for post-operative prophylaxis and to reduce the incidence of recurrence. Hydatid cyst should be considered in the differential diagnosis of mediastinal cystic mass, in particularly in endemic regions. The surgery most proposed in order to prevent severe complications1,7. References
Fig. 2. Operative view (resection of the germinative membrane of hydatid cyst of the superior mediastinum) L: Lung, C: Cyst, GM: Germinative membrane
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1. Kabiri el H, Al aziz S, El Maslout A, Benosman A. Hydatid cyst: an unusual disease of the mediastinum. Acta Chir Belg 2001; 101: 283–86. 2. Gormus N, Durgut K, Ozergin U, Solak H. Suppurated mediastinal and cardiac echinococcosis: report of a case. Surg Today. 2005; 35: 668–70. 3. Ozpolat B, Ozeren M, Soyal T, Yucel E. Unusually located intrathoracic extrapulmonary mediastinal hydatid cyst manifesting as pancoast syndrome. J Thorac Cardiovasc Surg 2005; 129: 688–89. 4. Purohit M. Primary hydatid cyst of the mediastinum. Eur J Cardiothoracic Surg 2003; 23: 257–58. 5. Bouchikh M, Ouadnouni Y, Msougar Y, et al. Pulmonary hydatid cyst presenting as dysphonia. Rev Mal Respir 2007; 24: 905–08. 6. Shameem M, Bhargava R, Ahmad Z, Fatima N, Nazir Shah N. Mediastinal hydatid cyst rupturing into the pleural cavity associated with pneumothorax: case report and review of the literature. Can Respir J 2006; 13: 211–13. 7. Kabiri el H, Zidane A, Atoini F, Arsalane A, Bellamari H. Primary hydatid cyst of the posterior mediastinum. Asian Cardiovasc Thorac Ann 2007; 15: e60-62.
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