[Two cases of fibromuscular dysplasia of the aorta (intimal hyperplasia)].

Two cases of this rare disease are described: in a 8-year-old girl and in a 6-year-old boy. In the former case there was a combination of a widespread damage to the aorta and coronary arteries while in the latter case intimal proliferation of the renal region of the aorta with stenosis of the renal arteries orifice were observed. Immunohistochemistry in this case showed intimal thickening in FMD to have a similar structure as in other processes. The cells of the smooth muscle type containing vimentin and some of them desmin showing a synthetic fibroplastic phenotype were found in the intimal polyps. The lack of apoprotein B in the deep layers allows to reject atherosclerotic nature of the processes. This observation confirms the opinion according to which intimal dysplasia should be recognized as a form of FMD.