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granulomas

Tuesday 10 June 2003

granuloma

Definition : Granuloma is a component of a specific form of chronic inflammation , called " granulomatous inflammation " observed in many diseases.

It is a round and well defined collection of immune cells known as macrophages (or histiocytes ).

Classically, granulomas form when the immune system attempts to wall off substances it perceives as foreign but is unable to eliminate. Such substances include infectious organisms including bacteria and fungi, as well as other materials such as keratin and suture fragments.

Digital slides

UI:872 - Foreign body granuloma (Foreign body reaction)

Images

https://twitter.com/ARTinPathology/status/558099263943884802

Definition: A granuloma is a solid grouping of inflammatory cells coming together in a lump or solid structure resulting from injury or inflammation or infection. Thus, granulomas are loosely defined as collections of inflammatory cells.

Classification

epithelioid granuloma

Epithelioid granulomas are well-demarcated and are composed of variable numbers of lymphocytes, occasional plasma cells, and prominent numbers of activated macrophages which have round to indented clear nuclei and abundant eosinophilic cytoplasm (epithelioid cells).

tuberculoid granuloma / epithelioid and gigantocellular granuloma

epithelioid cells and Langhans multinucleated giant cells
https://twitter.com/ARTinPathology/status/558099263943884802

inflammatory granuloma

Inflammatory granulomas are usually smaller than the epithelioid type and are composed of a mixed inflammatory infiltrate consisting of lymphocytes, macrophages, and occasional plasma cells, neutrophils and eosinophils.
These granulomas may or may not be poorly demarcated. Although occasional multinucleated giant cells can be seen, they are much less frequent than in the epithelioid granulomas.
A combination of both epithelioid and inflammatory granulomas may be seen within the same biopsy specimen.

necrotizing granuloma