[Mediastinal hydatid cysts: 8 cases]

Unusual clinical presentation of a giant left ventricle hydatid cyst

A 39-year-old woman was hospitalized in our center due to chest and left shoulder pain. Having a history of tamponade and tuberculosis, she was under treatment for the previous two months. Echocardiography, chest CT and MRI documented intramyocardial and pericardial hydatid cyst which was later confirmed by further pathological studies. Later, the cyst was removed surgically.

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.

[Mediastinal hydatid cyst. Reflections on a case study]

Hydatid cyst is a zoonotic cycle parasitic infection caused by Echinococcus granulosus tapeworm, whose larvae infect man as an intermediate host. It is one of the most serious lung diseases caused by helminths. It is rare to find it in the mediastinum; < 1%. The primitive, or seemingly primitive, location is due to the parasite in the cellular tissue of the mediastinum. The authors report the case of a sixteen year old male, admitted to the E.R. for left posterior chest pain which had spread to the upper left limb.

Mediastinal hydatid cyst rupturing into the pleural cavity associated with pneumothorax: case report and review of the literature

Hydatid disease remains a serious health problem in Mediterranean countries. Living in a rural area is an important risk factor for the disease. Hydatid cysts are usually located in the liver, lungs and brain. Mediastinal hydatid disease is very rare and has been noted only anecdotally in the literature. The present article reports a case of a mediastinal hydatid cyst rupturing into the pleural cavity, which was associated with pneumothorax of the same side. The patient's previous chest x-rays (posteroanterior and left lateral views) showed a well-defined mediastinal mass on the left side, and contrast-enhanced computed tomography of the thorax (taken a few days after the chest x-ray) showed multiple round-to-oval soft tissue opacities with partial collapse of the left lung. An indirect hemagglutination test for echinococcus was positive. Even after two weeks of intercostal tube drainage, the patient's condition did not improve. During thoracotomy, multiple daughter cysts were found in the pleural cavity, and the diagnosis of a hydatid cyst was confirmed after histopathological examination.

Suppurated mediastinal and cardiac echinococcosis: report of a case

We herein report the case of a suppurated mediastinal and cardiac hydatid cyst which occurred after the initial treatment of the patient for a primary mediastinal hydatid cyst in a radiology department. Both extracorporeal circulation and total circulatory arrest were used during the operation. We believe that surgery is the only feasible treatment for hydatid cysts located in the mediastinum, and surgery should be urgently performed whenever a possible rupture is suspected in order to avoid a possible anaphylactic reaction, mediastinal suppurations leading to serious complications, and growth into the pleural cavity.

MR findings in pericardial hydatid cyst

Pericardial hydatid cyst is rare. We present a 32-year-old man with a pericardial hydatid cyst. Chest x-ray film showed a spherical mass located left mediastinum. A pericardial cyst with low signal intensity was noted on T1 weighted magnetic resonance (MR) images. The cyst had high signal intensity, but signal intensity of folded parasitic membranes in the cyst were seen lower intensity on T2 weighted MR images. Based on these MR findings, pericardial hydatid cyst was diagnosed. The patient underwent surgical removal of the cyst. Histologic study of the cyst confirmed hydatid cyst diagnosis.

Hydatid disease from head to toe

Hydatid disease (HD) is a unique parasitic disease that is endemic in many parts of the world. HD can occur almost anywhere in the body and demonstrates a variety of imaging features that vary according to growth stage, associated complications, and affected tissue. Radiologic findings range from purely cystic lesions to a completely solid appearance. Calcification is more common in HD of the liver, spleen, and kidney. HD can become quite large in compressible organs. Hydatid cysts (HCs) can be solitary or multiple. Chest radiography, ultrasonography (US), computed tomography (CT), magnetic resonance (MR) imaging, and even urography can depict HCs. The imaging method used depends on the involved organ and the growth stage of the cyst. US most clearly demonstrates the hydatid sands in purely cystic lesions, as well as floating membranes, daughter cysts, and vesicles. CT is best for detecting calcification and revealing the internal cystic structure posterior to calcification. MR imaging is especially helpful in detecting HCs of the central nervous system. Radiologic and serologic findings can generally help establish the diagnosis of HD, but an HC in an unusual location with atypical imaging findings may complicate the differential diagnosis. Nevertheless, familiarity with imaging findings, especially in patients living in endemic regions, is advantageous in this context.

MR findings in cardiac hydatid cyst

We report a case of a 23-year-old man with a cardiac hydatid cyst involving the left ventricle wall. The diagnosis of the cyst was obtained by magnetic resonance (MR) imaging. He was operated on for cardiac hydatid cyst using enucleation and capitonnage procedure under extracorporeal circulation. Histopathologic study confirmed hydatid cyst diagnosis.