Collagen nature of asteroid bodies of giant cells in sarcoidosis.

STAR-sHAPED INCLUIONS have been observed in multinucleated giant cells as far back as 1890.1 Perhaps the most comprehensive study of the asteroid bodies, as seen under the light microscope is that of Cunnngham' who e d in 1951 that "in tests for collagen, Masson's trichrome stain and Mallory's connective tissue stain showed negative results. Wilder's stain for reticuhlm wa uni negative. Cunningham also concluded that the fining Of asteroid bodies in tuberculous and other epithelioid granulomas as well as in a variety of foreign body reactions strongly indicated that these inclsions we not specific for any disease entity. In a more recent review, Cunningham8 stated that asteroids are often seen in cases of sarcoidosis, either alone or associated with Saumnnnn bodies, and that 'histochemical and microincineration studies seem to indicate that these inclis are organic prein structures, possibly complex lipoyproteis. This paper deals with the fine structure of asteroid bodies in Langhans type, multinucleated giant cells of sarcoid granulomas. The finding that collagen fibers constitute the core of asteroid formations lends support to the thesis that epithelioid cells are capable of transformation ito fibroblasts during the healing of epitheloid granulomas. A preliminary eport of this work appears elsewhere.4