Granulomatous lung diseases

Abstract

Granulomatous lung disease is a heterogeneous group of diseases with different etiology, clinical symptoms and tissue damage, and different response to therapy. The prevalent histological sign of granulomatous lung disease is granuloma which is the clinical and morphological entity of this disease. The aim of this review was to describe a diversity of granulomatous diseases, key morphological features of infectious and non-infectious granulomatosis, and a diagnostic approach. Granuloma is a result of chronic inflammation involving cells of macrophage system and other inflammatory cells. Antigens activate T-lymphocytes, macrophages, epithelioid cells and polynuclear giant cells which form granuloma. Also, granuloma contains the extracellular matrix that is produced by fibroblasts and is intended to isolate the antigen. Granulomas could be infectious and non-infectious but, according to recent findings, microorganisms could cause granuloma formation in cases considered as non-infectious diseases. Therefore, sometimes it is difficult to estimate infectious or non-infectious origin of the disease.