Split the a general description of a trending topic from the reason it is trending right now.
The general description could be auto-snagged from Wikipedia or user-added - e.g. the information a person is a singer or television presenter, or the expansion of the acronym naming an event - and then a second section could explain why it is trending today - e.g. they just appeared on a certain show, or someone notable just spoke at the event.
Having a general description option along with actual reason will be a good feature, this should probably require login to edit and should be moderated to prevent spam. Also need API for this, if implemented...