Foreign body granuloma

A foreign body granuloma is a reaction to exogenous (foreign) or endogenous materials that are too large to be ingested by macrophages.

These localized lesions  may occur at any age and clinically present as papules, plaques or nodules.

Examples of granulomas due to exogenous material:

Starch (Maltese cross birefringence in polarized light)
Talc - birefringent
Suture material - (nylon, silk, dacron)- birefringent refractile multicoloured.
Wood splinter or bone fragment- Special stains for microorganisms should be performed to rule out infection due to contamination.
Plant material can be identified by PAS stain
Arthropod bite can cause granulomatous reaction
Silica (glass or sand ), zirconium & beryllium elicit sarcoidal granulomatous reaction.
Tattoo material- Extracellular pigment is identified and may induce local sarcoidal granulomas.
Tetanus toxoid (aluminium-adsorbed vaccines) may induce foreign body reaction. (Granular debris at the centre surrounded by histiocytes and lymphoid infiltrate with follicle & eosinophils at the periphery). May resemble Kimura's disease.
Silicone granulomas: A silicone granuloma is a tissue reaction elicited by silicone. Silicone granuloma in the breast arises from leakage of prosthesis. Foreign body giant cells are present near lacunar spaces filled with amorphous refractile material