Pulmonary complications of cystic echinococcosis in children in Uruguay.

Cystic echinococcal lesions surgically removed from 99 patients aged 1-15 years in Uruguay were histopathologically studied. The lesions were collected from the lungs, liver, peritoneum, omentum, pleura, ovary, appendix and perinephrium. All intact cysts were well-developed and unilocular. Pulmonary and hepatic fertile cysts in which protoscoleces were produced were in 75% and 47%, respectively, of all patients. Fertile cysts having many protoscoleces were in the lungs of a 1-year-old infant. Sixteen ruptured pulmonary cysts were found in the lungs of 13 patients and four ruptured hepatic cysts were found in the liver of three patients. Pulmonary complications were seen in patients having pulmonary echinococcal cysts. In lung tissue surrounding echinococcal cysts, pulmonary complications included chronic congestion, hemorrhage, bronchopneumonia, as well as interstitial pneumonia that included histological changes caused by bronchiolitis, organizing pneumonia and obstructive pneumonia. Liver tissue adjacent to echinococcal cysts showed atrophy of hepatic cells, proliferation of interstices, small focal hemorrhages, and infiltration of mononuclear cells. The present study shows that a close relationship exists between pulmonary echinococcosis and pneumonia. The term 'echinococcal pneumonia' is proposed for pneumonia accompanying pulmonary echinococcosis.