[Two cases of juvenile primary mediastinal hydatidosis]

Hydatid cyst disease is still a significant clinical problem in endemic regions. The lungs and the liver are most often involved in the child. A mediastinal localisation is rare and represents 0.1 to 4% of all cases of hydatidosis. The authors reports on two cases and provides a review of the literature. In a retrospective review of the last 12 years, the authors treated two cases with a mediastinal localisation out of total of 235 intrathoracic hydatid cysts arising in 222 patients (0.85%). Two girls, one 12 and the other 13 years old, were admitted with a previous history of chest pain. The chest x-ray revealed an homogenous opacity of 150 mm in the first case and 50 mm in the second. Computed tomography in the second case revealed a cyst in the posterior mediastinum. The abdominal ultrasound was normal in both cases. The patients were approached through a posterolateral thoracotomy and the diagnosis was confirmed macroscopically. The cysts were intact and located on the left side of the posterior mediastinum. The operative field was isolated and protected with hypertonic saline solution. Hydatid fluid was aspirated, followed by the extraction of the hydatid membrane and subtotal excision of the residual cavity in both cases. The postoperative course was uneventful without any relapse or other organ involvement during four and three years, respectively. The authors notes that hydatidosis should be considered in the differential diagnosis of a mediastinal cyst mass. Because of the benign nature of the disease, they emphasize that surgical treatment must be conservative.