Tularemic granuloma (g. tularaemicum) is a specific inflammatory formation that occurs with tularemia. It is a focus of necrosis surrounded by granulation tissue and containing the bacteria Francisella tularensis.
Granulomas form in organs and tissues where the pathogen enters when bitten by an infected tick, through damaged skin or mucous membranes. Most often, granulomas are localized in regional lymph nodes, liver, spleen and lungs.
Microscopy reveals a zone of necrosis in the center of the granuloma, surrounded by an accumulation of macrophages, lymphocytes and fibroblasts. A characteristic tuberous structure is formed with the presence of giant multinucleated cells of the Pirogov-Langhans cell type.
The presence of tularemia granulomas indicates a generalized form of the disease. Their formation plays an important role in the development of immunity, as it stimulates the production of antibodies and activation of T-lymphocytes. However, an excessive number of granulomas can lead to dysfunction of the affected organs.