An asteroid body is a microscopic finding seen within the

giant cells A giant cell (also known as multinucleated giant cell, or multinucleate giant cell) is a mass formed by the union of several distinct cells (usually histiocytes), often forming a granuloma. Although there is typically a focus on the pathological ...

granulomas A granuloma is an aggregation of macrophages that forms in response to chronic inflammation. This occurs when the immune system attempts to isolate foreign substances that it is otherwise unable to eliminate. Such substances include infectious o ...

in diseases such as

sarcoidosis Sarcoidosis (also known as ''Besnier-Boeck-Schaumann disease'') is a disease involving abnormal collections of inflammatory cells that form lumps known as granulomata. The disease usually begins in the lungs, skin, or lymph nodes. Less commonly a ...

and

foreign-body giant cell A foreign-body giant cell is a collection of fused macrophages (giant cell) which are generated in response to the presence of a large foreign body. This is particularly evident with catheters, parasites, or biomaterials that are inserted into th ...

reactions. There is controversy about their composition. Traditionally, they were thought to be

cytoskeletal The cytoskeleton is a complex, dynamic network of interlinking protein filaments present in the cytoplasm of all cells, including those of bacteria and archaea. In eukaryotes, it extends from the cell nucleus to the cell membrane and is compo ...

elements and to consist primarily of

vimentin Vimentin is a structural protein that in humans is encoded by the ''VIM'' gene. Its name comes from the Latin ''vimentum'' which refers to an array of flexible rods. Vimentin is a type III intermediate filament (IF) protein that is expresse ...

. However, more recent research suggested that that was incorrect and that they may be composed of

lipids Lipids are a broad group of naturally-occurring molecules which includes fats, waxes, sterols, fat-soluble vitamins (such as vitamins A, D, E and K), monoglycerides, diglycerides, phospholipids, and others. The functions of lipids include ...

arranged into bilayer membranes. They were also once thought to be related to centrioles, an organelle involved in

cell division Cell division is the process by which a parent cell divides into two daughter cells. Cell division usually occurs as part of a larger cell cycle in which the cell grows and replicates its chromosome(s) before dividing. In eukaryotes, there ar ...

in eukaryotes.

Additional images

Image:Asteroid body intermed mag.jpg, Micrograph of asteroid bodies in pulmonary

H&E stain Hematoxylin and eosin stain ( or haematoxylin and eosin stain or hematoxylin-eosin stain; often abbreviated as H&E stain or HE stain) is one of the principal tissue stains used in histology. It is the most widely used stain in medical diagnos ...

. Image:Asteroid body very high mag.jpg, Micrograph of asteroid bodies in pulmonary

. Image:Asteroid Body in Sarcoidosis.jpg, Asteroid body in sarcoidosis.

References

Histopathology {{Pathology-stub

See also

Additional images

References