Granulome annulaire élastolytique à cellules géantes : étude anatomoclinique

Abstract

Annular elastolytic giant cell granuloma (AEGCG), a rare entity first described in 1979, is very similar to O'Brien actinic granuloma (AG), first described in 1975. Since then, many cases have been published under one or other of the two names. We performed a single-centre histopathology study to identify the distinguishing features and determine whether there was any objective difference between AEGCG and AG. Cases classed as AEGCG or AG at the dermatopathology laboratory in Strasbourg were included and analysed using haematoxylin-eosin, orcein and Alcian blue staining. The diagnosis was made in the event of granuloma rich in multi-nucleated giant cells and reduction or disappearance of elastic tissue. Clinical data were collected from the analysis requests and clinical files. We identified 73cases: 12classed as AEGCG and 61classed as AG. Mean age was 60.5years with a sex ratio of 0.55. The duration of the disease ranged from 8days to 17years. A single lesion was seen in 52% of cases with multiple lesions in the remaining cases. Lesions measured between 0.3 and 10cm and exhibited a predilection for photo-exposed areas, chiefly on the head, neck and upper limbs. In most cases, an annular erythematous edge was seen together with a light centre, and slow centrifugal spread. The diagnosis was made by a clinician in only 5.5% of cases. These granulomas were chiefly in the superficial and mid dermis and only rarely deep, and contained numerous giant cells with a constant contingent of lymphocytes, but plasma cells were also seen in half of the cases. Orcein staining revealed marked decrease or total disappearance of elastic tissue within the granulomatous area together with elastophagocytosis in practically all images. More rarely, there was evidence of necrobiosis, palisading granuloma, vascular involvement or orcein-stained asteroid bodies. There were no notable clinical or histological differences between the cases initially classed as AEGCG or AG. AEGCG is a separate entity from annular granuloma that must be assimilated with O'Brien actinic granuloma. The central role of elastic fibres seems clear, but that of ultraviolet radiation remains more controversial. The term annular elastolytic giant cell granuloma seems more appropriate since it is more descriptive and carries no physiopathological implications. There appears to be a significant association with sarcoidosis and with diabetes in a minority of cases, thus warranting screening for these diseases.