Giant-cell hyalin angiopathy.

Seven examples of an unusual hyalin degenerative change in the walls of blood vessels are discussed. We believe this is a localized phenomenon, not connected to systemic vascular disease. Inflammation is usually present, and in each case a dental procedure had previously been performed. Dental extraction was the most common procedure. Giant cells of the foreign-body type are present, but particulate foreign material was seen in only one case.