[Histopathological and immunohistochemical diagnosis of intractable vasculitis syndromes]

Vasculitis has a simple definition--primary inflammation of the blood vessels, often with necrosis and occlusive changes--but its clinical manifestations are diverse and complex. In the absence of pathognomonic clinical features and laboratory tests, the diagnosis of vasculitis relies heavily on the correct interpretation of histologic changes but these too may not be specific in any given case. A positive biopsy is always helpful whereas a negative biopsy does not exclude the disease under consideration because the vasculitis may be focal and segmental in distribution, as in polyarteritis nodosa. Pathologic and immunohistochemical characteristics of some of the major categories of systemic vasculitis were described; 1) polyarteritis nodosa; 2) Churg-Strauss syndrome; 3) hypersensitivity vasculitis; 4) Wegener's granulomatosis; 5) Kawasaki disease; 6) malignant rheumatoid arthritis; 7) systemic lupus erythematosus; 8) scleroderma; 9) polymyositis-dermatomyositis; 10) mixed connective tissue disease; 11) polyangiitis overlap syndrome; 12) giant cell arteritis; 13) Takayasu arteritis; 14) Behçet disease; 15) Buerger disease; and 16) inflammatory aortic aneurysm. Each of these major vasculitic syndromes has its own unique histopathologic features, but overlap still occurs.