Pulmonary Hydatid Cyst Detected on FDG PET-CT

A 40-year-old man on follow-up for treated tongue cancer was evaluated with a chest radiograph for cough of recent onset. The radiograph revealed a lung mass which was diagnosed as hydatid cyst after surgical resection. Tapeworms of the genus Echinococcus cause hydatid disease in humans, which most commonly involves the liver. Pulmonary hydatid cysts may, however, be seen in isolation. These have varied imaging appearances and can often be mistaken for a lung mass or masses of more sinister origins. We describe the positron emission tomography-computed tomography appearance of a lung hydatid cyst.