[Variability among pathologists in the histological diagnosis of diffuse interstitial lung diseases]

Diffuse interstitial lung diseases (DILD) form a group of diseases which affect the alveolar interstitial space and share very similar clinical, radiological, and functional features, making lung biopsy essential for establishing diagnosis, prognosis, and treatment in many cases. We aimed to see whether there was agreement in histopathological diagnosis among different groups of pathologists in their assessment of these diseases.

Biopsies were studied from 33 patients suffering from noninfectious, nontumorous DILD. The biopsies had been assessed by 2 groups of pathologists: one specializing in this type of disease and another which was not a specialist group.

There was disagreement in the histology reports of 10 out of the 33 cases studied (30.3%): 9 cases in the group of 22 cases of idiopathic interstitial pneumonia (40.9%) and 1 in the group of 3 DILD with known or associated causes. No discrepancies were found, however, in the diagnosis of primary DILD or DILD associated with other, less well-defined processes.

We believe that idiopathic interstitial pneumonias are the DILD which pose most problems for pathologists. Therefore, the study of DILD requires specific dedication by pathologists and other professionals and specialists.