There are several granuloma types that can be found among humans and non-human primates, even within the same individual.
A. The classic tuberculous granuloma, found in active disease and latent infection, is the caseous granuloma, composed of epithelioid macrophages, neutrophils, a cuff of lymphocytes (CD4 and CD8 T cells, B cells) and sometimes surrounded by peripheral fibrosis. The center of this type of granuloma is caseous, a necrotic state that likely consists of dead macrophages and other cells. This area is hypoxic. Mycobacteria in this granuloma could be found in macrophages (either in contact with T cells or not) or in the hypoxic center, or possibly even in the fibrotic rim, leading to different microenvironments for the bacteria.
B. The non-necrotizing granuloma is usually seen in active disease, and consists primarily of macrophages with some lymphocytes; this lesion can be seen in guinea pigs and mice, albeit with more lymphocytes. M. tuberculosis bacilli are within macrophages in this lesion.
C. Fibrotic lesions are seen mostly in latent tuberculosis but also in active disease, and are composed almost completely of fibroblasts, with a minimal number of macrophages. Although it is possible to culture bacilli from some fibrotic lesions, it is not clear where the bacilli reside, perhaps in macrophages or in the fibrotic area, or what the microenvironment is like.