IContentTypeController typeController = new ContentTypeController();
ContentType contentType = (from t in typeController.GetContentTypes()
                           where t.ContentType == "DesktopModule"
                           select t).SingleOrDefault();
if(contentType == null)
{
    contentType = new ContentType {ContentType = "DesktopModule"};
    contentType.ContentTypeId = typeController.AddContentType(contentType);
}