Which biopsies in diffuse infiltrative lung diseases and when are these necessary?

Different biopsy techniques are used to obtain appropriate tissue for diagnostic pulmonary pathology. Traditionally open lung biopsies were more often used in the USA, whereas transbronchial biopsies prevailed in many European countries. However, the type of biopsy especially in interstitial lung diseases (ILD) should be selected not on traditional grounds, but on a scientific rationale. In progressive ILD where the pathologic diagnosis is based on the recognition of different patterns at different process stages, an open or video-assisted thoracoscopic lung biopsy is preferred, whereas in most granulomatous pneumonias transbronchial or even bronchial biopsies may suffice. For many other ILDs no recommendations exist, but will be tentatively given. In addition comprehensive clinical information should be provided for the pathologist, because this is the prerequisite for a qualitative diagnosis, which means not only a descriptive answer, but also an etiologically based one.