Abstract
Microscopic polyangiitis is a systemic small-vessel vasculitis that is associated primarily with necrotizing glomerulonephritis and pulmonary capillaritis. A recurrent and diffuse alveolar hemorrhage due to pulmonary capi llaritis is the main clinical manifestation of lung involvement. Recently, an interstitial lung disease that mimics idiopathic pulmonary fibrosis was reported to be rarely associated with microscopic polyangiitis. Here we report two patients with microscopic polyangiitis who showed a honeycomb lung at the time of the initial diagnosis with a brief review of relevant literature.