Histological features of nonspecific interstitial pneumonia

Abstract

Nonspecific interstitial pneumonia is a type of idiopathic interstitial pneumonia. By definition, the cases of nonspecific interstitial pneumonia are those which cannot be classified as any other type of interstitial pneumonia. The Material of the investigation included 12 transbronchial biopsy lung samples. The quantity, structure and distribution of specific cellular elements were determined semiquantitatively, recognizing three levels of the lesions' intensity: mild/ poor, moderate, and intense/abundant. The interalveolar septa were most frequently moderately thickened (50% of the cases) due to the presence of inflammatory cells and multiplied connective. Of the inflammatory cells, lymphocytes were most common and greatest in quantity (abundant, moderate and poor in 4, 5, and 3 cases respectively), followed by plasma cells and macrophages. The septal connective was moderately and mildly multiplied in 2 and 4 cases respectively. The lumen of the alveoli was infiltrated by lymphocytes and macrophages, while poor peribronchial and perivascular lymphocyte infiltrates were most commonly found. The interalveolar septa were most frequently moderately thickened due to the presence of chronic inflammatory cells, predominantly lymphocytes, as well as to mildly-to-moderately multiplied connective. The lymphocytes usually permeated the septa diffusely. Bronchiolar and blood vessel findings were nonspecific.