First image shows Asteroid Bodies and Secon image shows Scaumann Bodies.
- Sarcoidosis is a systemic disease of unknown etiology.
- It affects adults from 20-40 years of age.
- The disease is characterised by the presence of noncaseating epithelioid cell granulomas (‘sarcoid granuloma’) in the affected tissues and organs, notably lymph nodes and lungs.
- Other sites are the skin, spleen, uvea of the eyes, salivary glands, liver and bones of hands and feet.
Microscopically, the following features are present :
- The diagnostic feature in sarcoidosis of any organ or tissue is the non-caseating sarcoid granuloma, composed of epithelioid cells, Langhans’ and foreign body giant cells and surrounded peripherally by fibroblasts.
- Typically, granulomas of sarcoidosis are ‘naked’ i.e. either devoid of peripheral rim of lymphocytes or there is paucity of lymphocytes.
- In late stage, the granuloma is either enclosed by hyalinised fibrous tissue or is replaced by hyalinised fibrous mass.
- The giant cells in sarcoid granulomas contain certain cytoplasmic inclusions as follows: i) Asteroid bodies which are eosinophilic and stellate shaped structures. ii) Schaumann’s bodies or conchoid (conch like) bodies which are concentric laminations of calcium and of iron salts, complexed with proteins. iii) Birefringent cytoplasmic crystals which are colourless.