Morphological and structural variants of cellular and stromal interaction in a focus of destruction in acute lung abscess and lung gangrene in term of formation and stabilisation of fibrin-associated processes

Abstract

Purulent and destructive lung diseases are often complicated by loss of anatomic structure of lung tissue, development of lung cirrhosis with subsequent respiratory and heart failure. We performed pathomorphological examination of operational and post mortem lung tissue specimens from 116 inpatients of 25 to 78 years of age with acute lung abscess or lung gangrene who was treated at a pulmonology center from 1999 to 2005. Acute lung inflammation tending to suppuration was characterized by pronounced cell reaction with no "fibrin blockage" and resulted in extended histolysis and abscess formation. "Young" fibrin was often found. Microvessels were fully passable, full-blooded with no fibrin into lumen. At subacute stage, fibrin was "maturing" with subsequent organization and growth of granulated tissue. Clinically, there were sequestered lung abscesses. Massive deposits of "young" and "maturing" fibrin formed "fibrin cocoon" with macrophages and neutrophils bricked up inside. Cell reaction was weak. There were swelling and desquamation of endothelium of microvessels, massive fibrin deposits into vessel lumen and prominent perivascular impregnation with fibrin. This pathological variant could lead to formation of abscess or pulmonary fibrosis with carnification. In cases of massive subtotal or total, often bilateral lung injury with weak delimiting of purulent and destructive process massive destructive zones with resting lung parenchyma faintly impregnated with fibrin were seen. There were no features of fibrin deposition inside microvessels. Functional activity of neutrophils and macrophages was greatly decreased. Therefore, the most favourable pathohistological variant appears to be formation of fibrin blockage consisted of "young" fibrin deposits; prominent cell reaction and absence of microcirculatory block. Structural changes of cells and stroma should be considered during pathological examination in order to provide optimal treatment strategy.