Christmas Cancer
When a person, often a family member, who is highly attention seeking, makes up or exaggerates some kind of health event in proximity to a big holiday in order to create drama or put themselves in the center of plans. It is usually a vague but life-threatening illness, serious enough to cause others to drop what they're doing, but not specific enough that people will be aware of what actually ought to be happening to the person. Often after the goal is attained, the subject will let their dupes know that "the doctors found out everything was alright" - getting them off the hook for future issues.
Cousin 1: "Are you still not speaking to your mother-in-law?"
Cousin 2: "Nah, she's a liar. Remember two years ago when she got Christmas Cancer just to make sure we didn't go to grandma's, and 'recovered' just in time to go to the Bahamas?"
Cousin 2: "Nah, she's a liar. Remember two years ago when she got Christmas Cancer just to make sure we didn't go to grandma's, and 'recovered' just in time to go to the Bahamas?"