Diffuse lung disease in the current spectrum of immunocompromised hosts (non-AIDS)

Diffuse lung disease occurring in an immunocompromised patient is a nonspecific finding that may result from one or more of a variety of infectious and noninfectious causes. Patient history and clinical information are essential in narrowing the differential diagnosis, but in most patients, diagnostic procedures must be performed to determine appropriate therapy. Diagnostic possibilities include infection, spread of malignancy, reactions to chemotherapy or radiation, nonspecific interstitial pneumonitis, hemorrhage, and unrelated medical conditions. An understanding of the specific nature of the patient's immunologic defect and underlying disease allows one to predict the most likely organisms in cases of infection.