• 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.

•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.

•Common

•FB granulomas under the skin may be felt as a lump.

•Most other foreign body granulomas have little, if any clinical significance.

•Grossly, a foreign body granuloma may be visualized as a firm nodule, clearly distinguishable from the surrounding normal tissue.

•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.

• Current literature from PubMed at National Library of Medicine