Cutaneous sarcoidosis and foreign bodies. An electron probe roentgenographic microanalytic study.

A 60-year-old woman had extensive and recurrent foreign-body granulomatous inflammation of her forehead. The granulomata contained double refractile crystalline material. Electron probe roentgenographic microanalysis identified silicon, calcium, aluminum, potassium, and sulphur in the crystalline material. Silicon-rich particles are generally considered exogenous. A diagnosis of sarcoidosis was confirmed by the presence of bilateral hilar and mediastinal lymphadenopathy due to biopsy-proven nodal replacement by noninfectious noncaseating granulomata. We conclude that foreign matter may operate as a nidus for the formation of granuloma in sarcoidosis and that the presence of polarizable matter in a sarcoid granuloma does not rule out sarcoidosis.