New insights into gastrointestinal and hepatic granulomatous disorders

Abstract

Numerous diseases that involve the gastrointestinal tract reveal the presence of granulomas on histological analysis. Granulomatous diseases can be either primary or secondary to environmental factors. Granulomas are dynamic structures composed of organized collections of activated macrophages, including epithelioid and multinucleated giant cells, surrounded by lymphocytes. The formation of granulomas is usually in response to antigenic stimulation and is orchestrated through cytokines, immune cells and host genetics. In this Review, the pathogenesis and etiologies of granulomas of the gastrointestinal tract and liver are discussed, as are the available diagnostic tools to help differentiate their various underlying etiologies. In addition, the role of granulomas in harboring latent tuberculosis is reviewed. The effects of tumor necrosis factor antagonists and interferon-α on the development of granulomas are also discussed.

Clinical epidemiology and phenotypic characteristics of Crohn′s disease in the central region of Saudi Arabia

“…[37] A study from China demonstrated that granulomas were associated with a stricture-forming phenotype of CD. [38]…”

Macrophage-related diseases of the gut: a pathologist's perspective

“…However, pathogenic mycobacteria such as Mycobacterium tuberculosis and M. avium-intracellulare have developed mechanisms to prevent the fusion of lysosomes with phagosomes [45], resulting in survival and multiplication of the Mycobacteria in the phagosome, and in spread to other body parts when the macrophages migrate to other tissues. In immunocompetent hosts, prevention of this mycobacterial spread is achieved by the formation of a granuloma [46]. A granuloma sequesters infected macrophages in the center, surrounded by immune cells, predominantly CD4+ helper T lymphoctes.…”

Distinguishing between Crohn′s disease, tuberculosis, and lymphoma: Still in murky waters

“…[10] In this study, none of the cases with PIL had granulomas but their presence, although infrequent, has been described in patients with PIL in at least one other study. [6] A key feature from this study as well as others is that the presence of granulomas with caseous necrosis almost only occurs in patients with ITB.…”

“…A more recent marker that has been used histologically to differentiate ITB from CD granulomas, is the presence of mesenchymal cells bearing CD73 surface marker at the periphery of ITB granulomas. [4] In situ polymerase chain reaction (PCR) for ITB, although somewhat specific, still needs improvement in its sensitivity[101112] prior to its widespread implementation.…”