Pyelonephritis associated with Legionella pneumophila, serogroup 4.

A patient with bladder carcinoma metastatic to lung and brain died of pneumonia. Autopsy examination showed a confluent bronchopneumonia with several small abscesses and acute pyelonephritis with abscess formation. Legionella pneumophila, serogroup 4, was isolated in pure culture from lung tissue postmortem and was also shown by direct immunofluorescence in the kidney and spleen. In the kidney, the organism was noted in areas of acute pyelonephritis. This represents the first case of an extrathoracic inflammatory lesion associated with L. pneumophila.