Revisiting the retroperitoneal fibroses: are there any significant news about their aetiopathogenesis and diagnostic approaches?

BACKGROUND Many articles on retroperitoneal fibroses (RPFs), published over the last ten years, seem to set out as innovative the carried-out both diagnostic procedures and therapeutic measures, while a careful examination of the literature identifies them as a sheer application of previous acquisitions. Surely, instead, several interesting advances have been pointed-out in the field of pathogenesis, particularly regarding significant immunological correlations between yet so-termed idiopathic form and some systemic immune-mediated disorders. AIM To resume such topic as far as the pathogenetic implications are concerned, moreover taking into due consideration both the diagnostic modalities and, secondarily, the therapeutic measures innovatingly set out since the Eighties/Nineties of past century. AETIOLOGY The protean aetiopathogenesis of secondary RPFs is outlined, moreover up-to-dating an old taxonomic assessment. Before labelling a RPF as idiopathic any identifiable cause should be excluded as well as a possible correlation, synchronously or diachronously, with well-labelled multi-system autoimmune diseases, among whose the autoimmune responses to apoptosis-derived immunogenic material as primary source of autoantigens, the newly recognized hyper-lgG4-related sclerosing disease, besides well-known systemic fibrosclerotic disorders. DIAGNOSTICS, Laboratory findings may be sometimes consistent with a specific aetiology of secondary RPFs (e.g.: circulating anticeroid-antibodies, high both serum 5-hydroxy-thryptamine and urinary 5-hydroxy-indolacetic acid, elevated serum tumor markers). Since the Eighties, CT and MRI are the most suitable imaging modalities for RPF, often resorting to contrast enhancement nevertheless taking into account the risk of either iodinated contrast-induced nephropathy or Gd-based material-dependent "nephrogenic systemic fibrosis". Nuclear medicine, particularly with 18F-FDG-PET, besides to assess RPF "activity" and detect multi-focal fibroinflammatory diseases, can also tailor the therapeutic management according to dynamic course of the disease. CONCLUSIONS As against plenty of pathogenetic news, no innovative idea has been recently produced about diagnostics and therapy of RPFs, that might cause a knowledge structure break compared with the two last decades of the past century.