Cardiac Allograft Vasculopathy (VI)
An atheromatous plaque underlying a CAV lesion is shown in this image, in contrast to the non atherosclerotic CAV lesions. . This micrograph shows a Movat stain of a well established atheromatous plaque with a fibrous cap (yellow orange tissue in the area labeled atheromatous plaque)that developed in a long-term survivor. The gross pathology can be seen here. Early lesions tend to be more cellular than those in the late stages, where the smooth muscle cells decrease in number and the intima becomes fibrotic. Mononuclear inflammatory cells may be present in variable numbers, consisting mostly of T lymphocytes admixed with macrophages and foam cells. The internal elastic lamina is intact or only focally disrupted. The media is of normal thickness (red colored tissue) and shows no lipoprotein deposition. Medial fibrosis is seen in some lesions, towards the outer half, and may show lymphocyte-mediated injury of the vasa vasorum. An adventitial cuff of fibrous tissue (yellow / orange) with or without mononuclear inflammatory infiltrates is commonly observed. When atheromatous plaques are present, they are usually found in the proximal to middle segments of large epicardial arteries, produce an eccentric type of luminal stenosis, and histologically are indistinguishable from those of conventional atherosclerosis. In the small epicardial and intramyocardial branches, allograft vasculopathy is also concentric but foam cells are not prominent. A vasculitis type pattern of CAV can also occur.
