[Lung biopsy in interstitial pulmonary processes].

The value of open lung biopsies for the diagnosis of diffuse interstitial lung fibrosis is discussed. Except for few cases, e.g. granulomatous processes, needle biopsies are not a reliable method. In diffuse lung fibroses of unknown etiology which are not related to systemic diseases such as collagen diseases, combined electronmicroscopy and EDAX (Energy Dispersive X-ray Analysis) may reveal pneumoconiotic lesions due to unperceived mineral-dust exposure.