This pattern of injury is characterized by an irregular central zone of necrosis containing varying numbers of degenerating neutrophils and necrotic debris surrounded by poorly defined granulomatous inflammation with palisades of elongated macrophages and scattered multi-nucleated giant cells. This pattern of injury with central necrosis and peripheral palisading macrophages was well described in the seminal publications by Wegener [5] and later by Godman and Churg [8]. Some investigators have even concluded that find more this is essentially pathognomonic for GPA (WG). For example, Mark et al. [6] stated that: ‘Palisading granuloma is virtually pathognomonic

of Wegener’s granulomatosis whether or not it involves blood vessels.’ They go on to note that: ‘Compact granulomas

of tuberculoid or sarcoidal type did not occur in the cases of Wegener’s granulomatosis’. They contend that there is a very distinctive special form of granulomatous inflammation in patients with GPA (WG), but it is very different from more typical forms of granulomatous inflammation. Thus, the pathology of GPA (WG) warrants using the term granulomatosis in the name. As importantly, historical precedent also supports the use of the term granulomatosis in any new name for Wegener’s granulomatosis. As noted earlier, granulomatosis has been used in the modern medical literature primarily in the context of Wegener’s granulomatosis. Wegener initially used the term ‘rhinogenic granulomatosis’ for this disease. Further, this website Churg and Strauss used the term ‘allergic granulomatosis’ for what is often called Churg–Strauss syndrome [9], which is related closely to GPA (WG) and shares pathologically similar granulomatosis, polyangiitis and glomerulonephritis with GPA (WG). Microscopic polyangiitis (MPA) shares a systemic small vessel vasculitis

and pauci-immune necrotizing and crescentic glomerulonephritis with GPA (WG) and allergic granulomatosis (Churg–Strauss syndrome). All three diseases are also associated with anti-neutrophil cytoplasmic autoantibodies (ANCA), which appear to have a pathogenic role in these diseases. This substantiates the hypothesis made by Godman and Churg in 1954, based on pathology alone, that these three diseases are closely related and probably Ribonucleotide reductase share a common pathogenic mechanism [8]. Another issue that will be addressed by the 2011 CHCC is the role, if any, for ANCA serology in the diagnostic terms for GPA (WG), MPA and allergic granulomatosis (Churg–Strauss syndrome). For example, should this group (class) of vasculitides be called ANCA disease or ANCA-associated vasculitis, and should each clinicopathological variant name be prefixed by MPO-ANCA, PR3-ANCA or ‘seronegative’ (e.g. PR3-ANCA GPA, MPO-ANCA MPA, seronegative GPA, etc.)? There are clinical and pathophysiological arguments in favour [1,10] and against [10] this approach.