Random unrecognized file in dropbox

I have a file that was apparently shared with me that I can only open in dropbox from the recents section, all files, or menu bar on mac.  The file does not show up in any of the folders even though it says it's saved in "dropbox."  When I attempt to delete/remove the file I do not have any options that allow that.  I searched for a shared folder but there are none and strangely this file doesn't show up in the shared section.  It's some stupid sexual anime ( which of course my kids vehemently deny knowing anything about) so I am a little concerned about hacking but the file info says it was shared with me back in April and I've had no suspicious activity in my account.  Is this a support issue or am I just missing how to get rid of this file?