[O'Brien's actinic granuloma, Three cases (author's transl)].

We report three cases of 54, 58 and 65-year-old patients presenting annular lesions with centrifugal migratory extension. They occur exclusively on sun-exposed areas. In two cases, the lesions were multiple. In the third case, the lesion was single and mimicked an erythema annulare centrifugum. The past history ranged from 18 months to 8 years. Microscopic examination of the central part showed a disappearance of elastic fibers in upper reticular dermis. Examination of the ring showed in upper reticular dermis an histiocytic granulomatous infiltration with many giant cells, lymphocytes and patterns of elastic fibers phagocytosis. Similar features were found by electronmicroscopy. These three cases illustrate the typical features of O'Brien's actinic granuloma. Relationship between this actinic granuloma and granuloma annulare occurring on sun-exposed areas on one side, and necrobiosis lipoidica, Miescher's granuloma and granuloma multiforme on the other side, are discussed. On the basis of some clinical and histological patterns, the autonomy of O'Brien's actinic granuloma appears to be established.