Figure 1.
A and B, Representative photomicrographs comparing a transverse section of the ascending aorta of a healthy 2-year-old child (A) and the nonstenotic region of the ascending aorta of 2-year-old patient with WBS (B) (staining is with Movat's pentachrome; original magnification ×100). Nonstenotic regions of the WBS aorta demonstrate a larger-than-normal aortic-wall diameter, resulting from an increase in the number of SMC layers surrounded by abnormally thin elastic lamellae. C–E, Higher-power images of sections stained with Movat's pentachrome (magnification ×400), comparing the tunica media of the aorta of a healthy 2-year-old child (C) and the medial (D) and neointimal (E) layers of the stenotic region of the aorta of a 2-year-old patient with WBS. In contrast to the normal aortic tunica media composed of parallel elastic lamellae separated by single layers of SMC, in the stenotic region the lamellar architecture of the tunica media is disorganized and contains multiple clusters of SMC separated by thin, fragmented elastic fibers (D). The intimal thickening of the WBS aorta is composed of numerous SMC surrounded by elastin-poor ECM (E).