A case of polycystic hydatid disease with radiological manifestations that mimicked pulmonary metastatic lesions is reported. The patient, from Brasília, DF, was admitted to the Brasilia University Hospital in February 1996, with a six-month history of unproductive cough, progressive dyspnea, thoracic pain and an episode of hemoptysis. Besides the pulmonary lesions, a CT scan showed hypodense lesions and calcifications in the right lobe of the liver. Repeated examinations of the sputum and bronchoalveolar lavage revealed no malignant cells. An open lung biopsy was then performed and allowed the authors to recognize the helminthic nature of the disease. Protoscolices, probably of Echinococcus vogeli, were found in tissue sections. The source of infection was supposed to be some hunting dog lodged in a kennel kept by the patient. Administration of albendazole brought no significant improvement to the pulmonary lesions, after one year of treatment not yet interrupted.

Keywords: Polycystic hydatid disease. Polycystic echinococcosis. Neotropical echinococcosis. Echinococcus vogeli.