Based on a clinicopathologic study of 34 patients with biopsy-confirmed diffuse pulmonary
hemorrhage (DPH). we present an approach to the differential diagnosis of DPH with
attention to histologic features such as capillaritis and the importance of laboratory tests
such as anticytoplasmic autoantibodies (ACPA). The following DPH syndromes were
encountered: antibasement membrane antibody (ABMA) disease (four cases); idiopathic
pulmonary hemorrhage (four cases); Wegener's granulomatosis (WG)(five cases); probable …