[Multifocal fibrosclerosis (retroperitoneal, mediastinal, mesenteric and pelvic involvement) associated with vasculitis and revealed by a livedo: clinical, histopathological and ultrastructural study in a case (author's transl)].

A 22-year-old male patient was seen with vasculitis and subcutaneous nodules on arms and legs. Discret thoracic venous dilations were noticed and venography demonstrated obstruction of the superior vena cava. Clinical and biological examination, roentgenograms revealed no sign of immunological disease but led to the diagnosis of mediastinal and retroperitoneal idiopathic fibrosis. No drug could be incriminated. Right hydronephrosis obliged to a surgical bilateral ureterolysis combined with systemic steroid therapy. Histological and ultrastructural examinations on retroperitoneal biopsies showed dense collagenous fibrosis, with vasculitis. Perivascular infiltrate was mainly composed of extravased erythrocytes and lymphocytes. Fibrin deposits were seen around implicated vessels. Direct immunofluorescence investigations were negative. These morphological features seem to be in agreement with the physiopathological hypothesis of sclerosis. No retroperitoneal or mediastinal fibrosis extension occurred three years after surgical procedure, and under corticosteroid therapy. Similar vasculitis with mediastinal and retroperitoneal idiopathic fibrosis have previously been reported in only one case by R. W. Carton and R. Wrong. Multifocal fibrosclerosis is the generic term currently used, since Comings et al. (1967), to describe a group of fibrosing conditions which affect separate organ systems. Findings suggest that retroperitoneal fibrois, mediastinal fibrosis, sclerosing cholangitis, Riedel's thyroiditis and pseudotumors of the orbit may be different manifestations of a single disease whose pathogenesis remains obscure.