"Body Dysmorphia": this is where a person focuses on a part of their body they perceive to have flaws.
Now, a sympathetic person, such as most doctors, will want to "see" what you are supposedly seeing, and will be under the power of suggestion the same as anybody else. Had you walked in cold and said nothing about what you want examined and laid your hands on a table, the doc probably would have said, "So?" and "What brings you in?"
This is a common phobia or syndrome in anxious or nervous people.