<prompt> In acute inflammation the tissue response consists of all exceptVasodilationExudationNeutrophilic responseGranuloma formation  <response>: Ref Robbins9e p97 Granulomatous inflammation is a distinctive pattern of chronic inflammation characterized by aggregates of acti- vated macrophages with scattered lymphocytes. Granulo- mas are characteristic of ceain specific pathologic states; consequently, recognition of the granulomatous pattern is impoant because of the limited number of conditions some life-threatening that cause it Table 2-8. Granulo- mas can form under three settings: With persistent T-cell responses to ceain microbes such as Mycobacterium tuberculosis, T. pallidum, or fungi, in which T cell-derived cytokines are responsible for chronic macrophage activation. Tuberculosis is the proto- type of a granulomatous disease caused by infection and should always be excluded as the cause when granulomas are identified. Granulomas may also develop in some immune- mediated inflammatory diseases, notably Crohn disease, which is one type of inflammatory bowel disease and an impoant cause of granulomatous inflammation in the United States. They are also seen in a disease of unknown etiology called sarcoidosis, and they develop in response to rela- tively ine foreign bodies e.g., suture or splinter, forming so-called foreign body granulomas. 