Erythema gyratum repens. A case studied with immunofluorescence, immunoelectron microscopy and immunohistochemistry

Abstract
We report a patient with erythema gyratum repens (EGR), in whom a bronchial carcinoma was found. Direct immunofluorescence revealed granular deposits of immunoglobulins at the basement membrane zone (BMZ) in the skin, and in the lung tumour. Direct immunoelectron microscopy showed that the immune deposits were localized just beneath the lamina densa. Indirect immuno- fluorescence revealed circulating anti-BMZ antibodies. Immunohistochemical staining, using anti- transforming growth factor-β, anti-epidermal growth factor receptor, antivimentin and anti-α-actin, was found to be more intense in the lesional skin and the lung tumour than in normal tissues. Possible mechanisms in the pathogenesis of EGR are discussed.