Unintended percutaneous aspiration of pulmonary echinococcal cysts.

Three patients had viable, noninfected, echinococcal cysts of the lung unintentionally diagnosed by percutaneous transthoracic aspiration without deleterious effects. Although aspiration generally should be avoided in hydatid disease because of the possibility of allergic reaction or spread of disease, neither of these potentially adverse effects was seen. Cystobronchial communication was produced iatrogenically in all three cases. The patients were followed for up to 3 years 2 months. Two patients were treated with mebendazole. The pathologist should be alerted when clear colorless fluid is withdrawn from a chest mass because the scoleces of Echinococcus granulosus may be missed on routine staining.