II. Mechanisms of Granuloma Formation4

The process of granuloma formation in the lung is triggered, in most instances, by exposure to an antigenic stimulus. Although the numbers of many types of cells are increased in the lung, the antigen exposure leads, primarily, to an increase in the numbers of macrophages and T-lymphocytes. This increase in the numbers of macrophages and T-cells as well as their activation provides the appropriate environment for granuloma formation.