Perhaps you can use the WebBrowser control to display this content. An example of displaying data from a row in this control from the code behind would be:
webBrowser1.NavigateToString("<html><body><h1>Description</h1><p>This is a description, set from code</p></body></html>");
I am tempted to lower my bid for using invalid HTML markup, but that seems a bit harsh, doesn't it ?;)
In any case, if you want to bind to a property of the model, you will need to do additional work to establish the bindings. This blog post explains well how to add a dependency property that you can use to bind HTML strings in your models.