• A low power view showing many giant cells containing highly refractile (clear) foreign bodies within them.
• The green arrow points to a particularly large foreign body giant cell, containing a large foreign body.
|Foreign body granuloma|
•Almost any inert foreign body, such as pieces of glass, crystalline materials, talc, and pieces of soil can generate a foreign body granuloma.
•A foreign body granuloma is a reaction to inert foreign materials, that are too large to be ingested by either microphages (PMNs) or macrophages.
•FB granulomas under the skin may be felt as a lump.
•Most other foreign body granulomas have little, if any clinical significance.
|General Gross Description|
•Grossly, a foreign body granuloma may be visualized as a firm nodule, clearly distinguishable from the surrounding normal tissue.
|General Micro Description|
•Histologically it is composed of macrophages that have
differentiated into large cells with indistinct cell
boundaries called epitheloid cells.
•Some of these may fuse with each other to give rise to
"foreign body giant cells" - multinucleate cells often
containing ingested foreign material.
•Unlike the classical "immune" or Langhans type giant cell, in which the nuclei tend to be distributed along the periphery in a semicircle, leaving the center free of nuclei, the foreign body giant cell tends to have nuclei distributed randomly all over its cytoplasm.
|Cotran, Kumar and Robbins: Pathologic Basis of Disease,
5th Edition. W.B. Saunders & Co. 1994. pp 81|