ABSTRACT
Hydatid disease is a significant health problem in endemic areas. While occurrence of the cysts in the liver and lung is common, mediastinal localisation is extremely rare. We report the case of a 35-year-old male who presented with a painless swelling on the right side of the neck and features of superior vena caval obstruction. Chest radiography and computed tomography (CT) suggested a cyst in the right upper lobe, extending into the right supraclavicular region as well as another cyst in the left lung. Thoracotomy revealed that the right-sided cyst was actually mediastinal in location and had herniated through the thoracic inlet compressing the superior vena cava (SVC). Both cysts were removed in two separate operations and symptoms of SVC compression subsided after removal of the right-sided cyst. Histopathology was consistent with a hydatid disease.