A case of sinobronchial syndrome complicated with myeloperoxidase antineutrophil cytoplasmic antibody associated vasculitis: review of the literature.

We report a case of long-standing sinobronchial syndrome complicated by microscopic polyangiitis (MPA) during the clinical course. The patient showed a mild elevation of myeloperoxidase antineutrophil cytoplasmic antibody (MPO-ANCA) 17 months prior to the diagnosis of MPA. Subsequently, her MPO-ANCA level gradually became more elevated, and finally her MPO-ANCA level peaked when purpura appeared. Histologic examination of the skin biopsy was consistent with leukocytoclastic vasculitis. Based on the pathological and clinical findings, a diagnosis of MPA was made. Corticosteroid therapy finally led to a remission of MPA with normalized MPO-ANCA titers.