Reappraisal of thromboangiitis obliterans--a pathological contribution.

Thromboangiitis obliterans (TAO), the Winiwarter-Buerger disease, is a vasoocclusive disease of unknown etiology which typically affects medium-sized extremital vessels of young male smokers. While the diagnosis of TAO is largely based on patients' presentation and clinical criteria, pathological substrates have been poorly defined and repeatedly disputed. Comparing the histology and immunohistochemistry of TAO especially with those of arteriosclerosis obliterans (ASO) and thromboembolism in two larger studies, we recently identified several features with significant meaning for the differential diagnosis. The unique tissue appearance of TAO is in favor of a general disorder of minute vessels indicating periarteritis rather than pure endarteritis, whereas an inflammatory reaction directed to the internal elastic lamina corresponds with the severity of disease. Since TAO or its syndromic equivalent is probably more common than currently diagnosed, the presented pathological criteria may help to identify latent cases, the overlap with ASO, and untypical organ involvement of TAO.