Unexplained pulmonary infiltrates in the compromised patient. An invasive investigation in a consecutive series

A series of 51 consecutive unexplained pulmonary infiltrates were reviewed retrospectively, in a group of 48 patients in whom invasive procedures were performed. Fifty-two percent of these patients had leukemia or lymphoma and 40% had solid tumors. All patients had lung tissue obtained premortem either by transbronchial biopsy through the flexible fiberoptic bronchoscope or by open lung biopsy. There was a 27% complication rate in these invasive procedures including bleeding, pneumothorax, and ventilatory support. Infectious agents were found in only 13 cases (25%) with a mortality rate of 62%. The pathologic finding of the underlying malignant disease or organizing pneumonia portended a poor prognosis with 100% and 80% mortality, respectively. Twenty-one patients had biopsy tissue revealing only nonspecific pathologic changes and were associated with the lowest mortality (19%). It was found that 50% of the solid tumor patients with unexplained pulmonary infiltrates had nonspecific pathologic changes. The biopsy findings resulted in a change in the therapy in 29% of the cases and in 19% of the cases the subsequent change in therapy resulted in marked improvement. The lung biopsy is useful to diagnose treatable infectious disease, as well as for prognostic guidance in caring for critically ill compromised patients.