Pleural empyema in a patient with a perinephric abscess and diaphragmatic defect

Pleural infection as a complication of ascending urological infection is rare, and the mechanism often unclear. We report a complicated case of pleural infection and perinephric abscess in a patient who presented with a large right-sided pleural effusion. Pleural fluid culture yielded Morganella morganii, an unusual pathogen in pleuro-pulmonary infections. Her computed tomography (CT) scan of abdomen showed a right perinephric abscess which extended into the pleural cavity. Review of prior CT imaging suggested a pre-existing diaphragmatic defect, likely representing a congenital Bochdalek foramen, through which the infection ascended. Successful treatment was achieved with systemic antibiotics, and drainage of both the pleural and retroperitoneal collections. Intra-pleural tissue plasminogen activator/deoxyribonuclease therapy effectively cleared the residual pleural fluid. Spread of intra-abdominal sepsis through diaphragmatic defects to the pleural cavity represents a potential source of empyema.