Electron microscopic and immunohistochemical investigation of Reinke's edema.

Examination was made of the vocal fold mucosa of Reinke's edema immunohistochemically and electron microscopically, with special attention to blood vessels in Reinke's space (RS). Ten surgical specimens of Reinke's edema were used, and the results obtained are summarized as follows. There were subepithelial vascularization and many dilated vessels in RS. The vessels had thin endothelium with many fenestrae, many vesicles, and a thickened basement membrane. Plasma exuded from the capillaries into surrounding tissue via fenestrae. These findings demonstrate increased permeability of the vessels. The vascular walls were thin, with few pericytes. The pericytes were situated away from the endothelial cells. Some endothelial cells and pericytes had degenerated, and vessel occlusion was apparent in some cases. These findings indicate the vessels had become fragile. Interstitial cells and/or inflammatory cells in RS showed stained cytoplasm with vascular endothelial growth factor. This growth factor may possibly enhance capillary permeability and form fragile vessels in RS. Fragility and alteration in permeability of the vessels are presumed to cause edema of RS, which may progress to Reinke's edema.