Pathogenesis and cause of death in a case of idiopathic infantile arterial calcification (IIAC) was discussed from the standpoint of morphological pathology.
(1) It seems reasonable to consider that myointimal and medial smooth muscle cells may induce congenitally abnormal metabolism and structure of the elastic fibers in the vascular wall. Deposition of calcium and iron on the arterial wall and intimal proliferation are only the secondary phenomenp to elastic fiber abnormality.
(2) Heart failure was caused by narrowing of the vascular lumen by intimal thickening and increased loading of the heart due to infection, which might accelerate ischemia in the myocardium based on the established coronary arterial lesion of IIAC.
(3) Deposition of basophilic substance on the arterial wall does not necessarily mean pure calcium deposition, so that IIAC may be a misnomer.
In adults, metabolism of insudated lipoprotein into the arterial wall has been considered to play a main role in the development and progression of arteriosclerosis. However, the arterial lesion in this case reminds us of an importance of functions of the internal elastic lamina and smooth muscle cells. This is a very suggestive case in the study of factors of progression of arteriosclerosis, in relation to function of the internal elastic lamina.