Granuloma Annulare: On It's Histogenesis

Abstract

A biopsy was performed from a skin lesion of a patient with multiple granuloma annulare, and examined under light and electron microscopes and by means of monoclonal-antibodies technique. Histologically it was diagnosed as mononuclear infiltrative type of granuloma annulare. Electron microscopically in the cytoplasm of many epithelioid cells located centrally in the lesion, there were well-developed mitochondria and lysosome-like granules which were specific for the cell in monocyte-phagocyte system, but neither phagosome nor secretory lysosome, whereas the secretory type of lysosome were specifically seen in epithelioid cell in the skin lesion of typical sarcoidosis. It was also revealed by means of monoclonal antibodies techniques that Leu 3a+ cdlls and Leu 2a+ cells were found in the periphery of the lesion and the former was more prominent in number than the latter. There was no deposition of any immunoglobulins in the lesion except that of C3, which was found at the vessel-walls. Basing on the findings obtained in our study and from literatures, we discussed on the histogenesis of granuloma annulare from a immunopathological point of view. © 1986, Meeting of Osaka Dermatological Association. All rights reserved.