[Non-resolved pneumonia--a diagnostic and therapeutic dilemma]

A persistent pulmonary infiltrate, infiltrates which take many weeks to resolve or recurrent pulmonary infiltrates are a diagnostic challenge. In establishing diagnosis, invasive methods such as bronchoalveolar lavage or lung biopsy are often unavoidable. The terms "persistent pulmonary infiltrates of noninfectious etiology", "slowly resolving pneumonia", "non-resolving pneumonia" and "recurrent pneumonia" are defined and their underlying causes are discussed in detail.