This scanning electron micrograph (SEM) depicted a number of red blood cells found enmeshed in a fibrinous matrix on the luminal surface of an indwelling vascular catheter; Magnified 7766x. In this instance, the indwelling catheter was a tube that was left in place creating a patent portal directly into a blood vessel. The erythrocyte in the center had undergone the process of 揷renation?, whereupon, it developed a number of cell wall projections, thereby, transforming it into what is termed an 攁canthocyte?, or 攕pur cell?.