Unusually located intrathoracic extrapulmonary mediastinal hydatid cyst manifesting as Pancoast syndrome

Hydatid cyst still remains an important problem in developing countries. It can appear in any place throughout the body and is more common in the liver (75%) and lung (25%).(1) The lung is the second most common site of location, but because of its elastic properties, hydatid cyst seldom shows intrathoracic compression signs and symptoms unless the size is too huge. Compression signs and symptoms can be seen when the cyst is located in the extrapleural or mediastinal region. A few cases of hydatid cyst have been reported as a benign cause of Pancoast syndrome in the English literature. Here we present an unusual compression of extrapleurally located mediastinal hydatid cyst causing Pancoast syndrome.