Fig. 1.

Representative photomicrographs show mild, moderate, and severe medial degeneration in histologic sections stained with hematoxylin-eosin (A, C, E) and Verhoeff–van Gieson elastic tissue stain (B, D, F). A) Mild medial degeneration exhibits a mild increase in basophilic intralamellar MEMA (arrow) in a section stained with hematoxylin-eosin and (B) the mild loss of elastic fibers (arrow) in a section stained with elastic tissue stain. C) Moderate medial degeneration shows a multifocal increase in intralamellar MEMA (arrow) and (D) multifocal attenuation of elastic fibers (arrow). E) Severe medial degeneration exhibits multifocal translamellar MEMA (arrow) and (F) multifocal translamellar loss of elastic fibers (arrow). Each scale bar represents 100 μm; original magnification for all images is ×50.

MEMA, mucoid extracellular matrix accumulation.