Uncommon presentations of primary systemic necrotizing vasculitides: the Great Masquerades.

Introduction: Systemic vasculitides are great masqueraders and at times their presenting manifestations can be very different from the usual recognized patterns. Such uncommon presentations of granulomatosis with polyangiitis (Wegener's granulomatosis), classical polyarteritis nodosa and unclassifiable vasculitides are described here with the relevant review of literature.

Methods: All patients diagnosed as having systemic vasculitides and classified as having granulomatosis with polyangiitis (Wegener's granulomatosis), classic polyarteritis nodosa, microscopic polyangiitis and unclassifiable vasculitis according to EMEA consensus methodology and followed up prospectively from June 2007 to December, 2011 were included. Details of uncommon presentations of these disorders were identified.

Results: Seventy-nine patients with systemic vasculitides were seen under our rheumatology services during this period. These included 45 patients with granulomatosis with polyangiitis (Wegener's granulomatosis), 18 with classic polyarteritis nodosa, five with microscopic polyangiitis, four with Churg-Strauss syndrome and seven with unclassifiable vasculitis. The uncommon presentations of granulomatosis with polyangiitis were a tumefactive subcutaneous mass in the thigh; prostatomegaly with obstructive uropathy and advanced renal failure; and predominant gastrointestinal (GI) vasculitis with thrombocytopenia and coagulopathy at presentation. The uncommon manifestations of classic polyarteritis nodosa were secondary antiphospholipid antibody syndrome and Budd-Chiari syndrome. One patient with massive lower GI bleeding required surgical resection of the large bowel which showed isolated necrotizing granulomatous GI vasculitis. Single organ vasculitis of the GI tract was diagnosed.

Conclusions: Systemic necrotizing vasculitides may present with uncommon manifestations and a high index of suspicion is required for early diagnosis and prompt treatment to prevent adverse outcomes.