[Etiology and morphogenesis of the socalled bronchial arterioma (author's transl)].

Angiomatoid vascular convolusions may develop during the intrapulmonic course of the bronchial artery. The angiomatoid convolusions are arranged segmentally along the longitudinal axis of a bronchus. Histopathologic examinations of 26 cases reveal that the angiomatous lesions form from branches of the bronchial artery, arterial bronchopulmonic connections and their arteriovenous anastomoses, as well as from branches of the pulmonary artery and vein. Common morphologic findings include marked tortuosity with branching, variable lumens, stenosing intimal scars, thrombotic occlusions, pronounced longitudinal muscle bundles and focal necrosis of the vessel wall. Such vascular formations, usually confined to one lung segment, may arise from inborn malformations in this vascular area. Such cases are to be called angioma arteriovenosum racemosum (5 cases from our material). In 21 observations however they have developed secondarily following primary inflammatory, stenosing or deforming diseases of the bronchus, the peribronchial tissues and the surrounding lung tissues. In such cases the angiomatoid changes are the consequence of local stress on blood vessels, blood flow and blood presssure; they do not develop on the basis of a congenital bronchial or vascular dysplasia. We propose the term secondary angiomatoid vascular convolusions in a scarred, deformed bronchial wall or peribronchial tissue. Pulmonary hypertension does not accompany the angiomatoid lesion and their clinical significance lies in dangerous hemorrhages into the bronchial tree.