Malignant atrophic papulosis (Degros disease). A report of two cases with clinical and histological studies.

Two women had malignant atrophic papulosis that affected the skin only. Immunologic studies showed normal amounts of serum immunoglobulins and complement and normal delayed hypersensitivity skin test results. Fibrinolysis autografts showed complete loss of fibrinolysis within the lesions but normal fibrinolysis in uninvolved skin. Histopathologic studies showed moderate inflammatory infiltration consisting of lymphocytes in addition to the typical cone-shaped regions of necrobiosis. Large amounts of mucin also were seen. Endovasculitis, thrombosis, and perivascular lymphocytic inflammation were noted in the subcutaneous arterioles of the lesions in only one of the patients. Enzyme histochemical studies showed oxidative enzymes, although in reduced amounts, in the epidermal and dermal cells of the affected skin. Electron microscopic studies of lesions showed paromyxovirus-like inclusions in endothelial cells and fibroblasts. The possibility of an unusual viral causation should be examined further.