Primary hydatid cyst of the posterior mediastinum

Hydatid Disease: A Pictorial Review of Uncommon Locations

Hydatid disease is a zoonotic infection caused primarily by the tapeworm parasite, Echinococcus granulosus. It is considered an endemic disease in the Mediterranean region.  In about 90% of cases, hydatid cysts are found in the liver and lungs; however, any other organ in the body may be affected, particularly in endemic areas. When encountering cystic lesions in these areas, the physician should always keep hydatid disease as a possible diagnosis in mind. To avoid life-threatening conditions such as anaphylactic shock or pressure effect on vital organs, timely diagnosis, and proper management are critical. When a rare site is involved, hydatid disease should be diagnosed using a combination of serologic assays and imaging modalities such as ultrasonography, computed tomography (CT), and magnetic resonance imaging (MRI). These imaging modalities can also be used to determine the extent of the disease and assess possible complications. Here, we present a pictorial review of typical imaging manifestations of hydatid cysts in unusual sites. Being aware of these imaging features will assist physicians in making an accurate, timely diagnosis and subsequently, providing optimal management.

Mediastinal calcified hydatid cyst

Mediastinal hydatid cyst is a rare disease and should be considered in differential diagnosis of mediastinal cystic lesions especially in endemic regions. This localization is very serious because of the surrounding vital structures. Surgery must be indicated immediately using conservative techniques without extensive resection when progression of dissection is difficult or dangerous. Medical treatment is necessary to prevent recurrence.

An unusual cause of posterior mediastinal cyst

Cystic lesions of the mediastinum may be congenital or acquired. The differential diagnosis depends on their location in the mediastinum. Cysts in the posterior mediastinum are generally developmental cysts and are neurogenic or of foregut origin. We report the case of a 14-year-old boy, who presented with dry cough and progressively increasing breathlessness, and was found to have a cystic lesion in the posterior mediastinum. Fine needle aspiration from the cyst helped make a diagnosis of tuberculosis.

Aggressive hydatid cysts: characteristics of six cases

PURPOSE

Hydatid cyst (HC) disease is a zoonotic disease caused by the larvae of Echinococcus granulosus. We report our experience of treating HC manifesting aggressive characteristics.

METHODS

Between January, 2010 and December, 2013, 40 patients underwent surgery for HC disease in our department. The subjects of this study were six patients whose disease followed an aggressive and invasive clinical course. The HC disease in these patients involved the vertebrae, chest wall, mediastinum, diaphragm, and lung, with destruction of the lung.

RESULTS

There were four men and two women, with a mean age of 47 years (range 12-81 years). Treatment consisted of cystectomy and additional procedures, such as corpectomy and resection of the chest wall, approaching the liver and spleen with phrenotomy and lobectomy. One patient suffered prolonged biliary drainage, and another had a bronchopleural fistula and atelectasis. One patient died of empyema 1 month postoperatively. The mean hospital stay was 9 days.

CONCLUSION

In some patients, HCs can act as an aggressive tumor, involving the surrounding tissues, organs, and even bony structures. Aggressive HCs may cause various sequelae and require extended surgical interventions in addition to cystectomy.

Atypical localizations of hydatid disease: experience from a single institute

Introduction:

The hydatid disease most often involves the liver and the lungs. The disease can involve any part of the body except the hair, teeth and nails. Primary extrahepatico-pulmonary hydatid cysts are rare and only a few sporadic cases have been reported.

Materials and Methods:

Two hundred and forty-four patients with hydatid cysts managed surgically from January 2005 to December 2009 were evaluated retrospectively. Fourteen (5.7%) patients had isolated involvement of the atypical sites, while six (2.4%) also had a primary involvement of liver.

Results:

The cysts were present in gall bladder (0.4%), peritoneum (1.6%), spleen (1.6%), ovary (0.4%), subcutaneous (0.8%), seminal vesicle (0.4%), spinal (0.4%), pancreas (0.4%), kidney (0.4%), mediastinal (0.4%), muscle (0.4%), and brain (0.8%).

Discussion and Conclusions:

Involvement of sites other than liver and lungs by hydatid disease is rare. Symptoms are related to size, location or possible complication of the cyst. It should be strongly suspected in differential diagnosis of all abdominal cysts especially in an endemic area. Proper surgical and medical management to avoid any recurrences, and a regular follow-up, are of utmost importance to detect any late complications such as local recurrence of the disease and development of hydatidosis at the primary sites.

Primary mediastinal hydatid cysts

PURPOSE

Hydatid disease is endemic in many parts of the world. Mediastinal hydatidosis is seen less than 0.1% of all hydatid diseases. We want to report our primary mediastinal hydatid cysts.

MATERIALS AND METHODS

In this retrospective study, from January 2010 to December 2012, 158 patients with intrathoracic hydatid cysts were operated in our thoracic surgery clinic. Nine of 158 (5.69%) patients had mediastinal hydatid cyst. Chest X-ray and computed tomography (CT) were used as diagnostic tools.

RESULTS

Hydatid cyst was confirmed surgically and pathologically in all the patients. Anterior mediastinal hydatid cysts and one cardiac involvement were determined in our study. While total cyst excision was performed in seven patients, partial pericystectomy could be done in two patients. In one patient, left ventricle invasion was seen and it was totally excised. Postoperative albendazole was applied to patients and there was no recurrence of disease till now.

CONCLUSIONS

Mediastinal hydatid cysts are uncommon and should be kept in mind in differential diagnosis of mediastinal cystic lesions especially in endemic regions. Surgical resection must be done and then medical therapy is needed to prevent recurrence.

Unusual mediastinal dumbbell tumor mimicking an aggressive malignancy

Hydatid cyst is known to affect all possible anatomical locations of the human body. However, the mediastinal localization is extremely rare. This benign, commonly asymptomatic and incidentally detected disease, at times may simulate an aggressive malignancy by its potential to cause osseous destruction and intraspinal extension. A young female, farmer by occupation, presented with complaints of left chest pain and monoparesis of the left lower limb. Radiograph followed by computed tomography (CT) of the chest demonstrated a cystic mass within the posterior mediastinum, eroding and scalloping overlying ribs and extending into the spinal canal by causing destruction of adjoining vertebra, and assuming a dumbbell shape. The serology was positive for echinococcosis. The patient underwent surgery and the postoperative histopathology confirmed the diagnosis of hydatid cyst. The patient recovered with no complications or recurrence. Hydatid cyst should always be considered in the differential diagnosis of mediastinal cystic lesions, however aggressive the lessions may appear.

Mediastinal hydatid cyst

BACKGROUND

The objective of this study was to report our experience in the management of hydatid cysts of the mediastinum.

METHODS

Among 206 patients who underwent surgery in our department for intrathoracic hydatid cysts between September 2001 and September 2008, 7 patients (3.4%) aged 24 to 49 years (mean, 36.2 years) had mediastinal hydatid cysts. Imaging consisted of chest X-ray and computed tomography. Surgical approach was by posterolateral thoracotomy in all cases.

RESULTS

The cyst was located in the posterior mediastinum in 3 cases (42.8%), in the anterior mediastinum in 2 cases (28.5%) and in the middle mediastinum in 2 cases (28.5%). Two patients had cysts in other thoracic locations (diaphragm, pleural). All cysts were intact. Surgical approach was right thoracotomy in 5 patients (71.4%) and left thoracotomy in 2 patients (28.5%). In 5 cases, a small part of the cyst wall intimately adherent to vital structures was left in place. There were no postoperative complications or mortality.

CONCLUSION

Mediastinal hydatid cyst is an uncommon disease. Because of the surrounding vital structures, the cyst should be removed immediately. Surgical removal remains the treatment of choice for mediastinal echinococcosis, without extensive resection when progression of dissection is impossible or dangerous.

Primary mediastinal hydatid disease leading to popliteal artery hydatid cyst embolization

Hydatid disease is a zoonosis caused by Echinococcus granulosus . Infected dogs release eggs through their feces and the eggs infect humans through food and water. The most common locations of hydatid cysts are the liver and lungs, but primary mediastinal involvement, though rare, can be encountered. We report on a 16-year-old female with a primary mediastinal hydatid cyst leading to popliteal arterial embolization. The mediastinal lesion was treated with partial pericystectomy with removal of the germinal membrane and prophylactic albendazole. In endemic areas, it is important to consider hydatid cysts in the differential diagnosis of an acute arterial occlusion.