The pathology and pathogenesis of malignant atrophic papulosis (Degos' disease). A case study with reference to other vascular disorders.

The morphology and immunohistology in a case of malignant atrophic papulosis (Degos' disease), a rare vascular disorder of unknown etiology, are described. The vascular lesions affected middle class and small arteries and veins throughout the body and were histologically characterized by intimal proliferation in the absence of any appreciable inflammation. The lesions were categorized as early, intermediate or late. Early lesions consisted of cellular proliferation and edema of the intima with signs of immune complex deposition (IgM, C3). Thrombosis was occasionally present as a secondary phenomenon in the affected vessel segments. In intermediate lesions the edema decreased and smooth muscle proliferation became apparent. Late lesions consisted of acellular intimal sclerosis with hyalinization and narrowing or obliteration of the vascular lumen. The media of the vessels remained always intact. In comparing these features to the pathology and pathogenesis of other vascular disorders they resembled the vascular lesions in a murine model of lupus erythematodes in which also considerable intimal proliferation occurred with thrombotic occlusion, but without appreciable inflammation. The murine model is associated with sustained low levels of circulating immune complexes and it is tempting to assume the same for Degos' disease. The notion of an immune complex mediated non-inflammatory condition underlying this severe and often fatal vascular disorder of mainly young males may contribute to the eventual finding of a successful therapeutical regimen.