Gross appearances: The heart weighed 450 g (normal 300 g). A secundum-type atrial septal defect, 2 cm in diameter, was present. Valves were normal. The right ventricle was 1.2 cm thick (normal <0.5 cm), and the left ventricle was 1.5 cm thick. The lungs (right 350 g, left 310 g (normal)) were normal except for marked atherosclerosis of the main arteries and prominent thickening of walls of small arteries.
Histologic Changes
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These two photos illustrate the characteristic lesion in this disease. Each picture shows a parent artery to the right (arrow) that gives rise to a larger mass of thin-walled channels, which in turn open into dilated, thin-walled vessels (asterisks mark three) that connect with the alveolar capillary bed. | ||||||
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These lesions are infrequent, present in 4-7% of muscular arteries, and not present in every patient. What are they? Answer | ||||||
Answer: The plexiform lesion of plexogenic angiopathy
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This plexiform lesion is composed of angioblastic, granulation tissue that has partially destroyed the wall of the parent vessel (arrow). The bluish tinge of the matrix suggests that the lesion is actively progressing. The plexiform channels then lead into large dilation lesions (* mark a few). Thrombosis (T) and recanalization are components of the remodeling in the angioblastic process. | ||||||