Cutaneous sarcoidosis and foreign bodies.

A histopathological diagnosis of sarcoidosis is, by convention, one of exclusion and is reached only when other potential causes of granulomatous disease, such as foreign bodies, are eliminated. We report herein three cases of systemic sarcoidosis with cutaneous manifestations of the disease, in which polarizable foreign particles were associated with the granulomata in the skin. We submit (a) that a granulomatous foreign body reaction and sarcoidosis are not mutually exclusive, (b) that particulate foreign matter may actually serve as a nidus for granuloma formation in sarcoidosis, and (c) that the occasional presence of extraneous material within the granulomata of sarcoidosis requires greater recognition by pathologists.