General non infectious Granulomas

Question 1

what is the difference between histiocyte and macrophage ?

Answer 1

DCs, monocytes, and macrophages are members of the mononuclear phagocyte system,2 whereas a histiocyte is a morphological term referring to tissue-resident macrophages. Macrophages are large ovoid cells mainly involved in the clearance of apoptotic cells, debris, and pathogens.

Question 2

what unifies non infectious granulomas ?

Answer 2

they are unified by similar histologic findings despite having disperate often unknown causes.
They are defined by their cutaneous inflammatory infiltrate, consisting of histiocytes, macrophages, giant cells, and granuloma formation.

Question 3

what are diseases defined as non infectious granulomatous disorders ?

Answer 3

1) Sarcoidosis
2) Necrobiosis Lipoidica
3) Granuloma annulare
4) Annular elastolytic giant cell granuloma
5) Cutaneous Crohn disease
6) Foreign body granuloma
7) Interstitial granulomatous dermatitis
8) palisaded neutophilic and granulomatous dermatitis.
All the above are discussed in depth in chapter 93.

Other non infectious granulomatous diseases :

• • Rheumatoid nodule- ch 45
• • Granulomatous Cheilitis - ch 72
• • Foreign body granulomas - ch 94
• • primary immunodeficiency-associated granulomatous dermatitis- ch 60