A thrombus is blood that has clotted in the heart or a blood vessel. This thrombus occludes the vein. (Fixation has made it shrink away from the wall.) Note the different shades of pink and red in the clot itselt. These are the "lines of Zahn," confirming that the thrombus formation occurred over time. Some layers of the thrombus will be richer in fibrin and others will be richer in platelets, thus the different layers of color.

One of the most important concepts in pathology, "Virchow's Triad"...

Whenever you see a thrombus, at least one of these factors has been operating.


Meet me
Visitors to Tom Demark's
website since Sept. 1999