My boyfriend has this little piece of cartilage the size of a small grape on the right side of his neck just below the level of his Adam's Apple. I think it's cute, but he HATES it when people touch him there, even doctors. I think it might tickle him somewhat, because his whole body jerks to protect that spot if he even THINKS someone is going to touch him there. He says it's a birthmark he's had all of his life... but I thought birthmarks were like bruises...? So what is it, if not a birthmark?
PS/ It's not cancer or troll aids. The doctor says it's nothing to worry about.
PSS/ I still like to poke him there every once in a long while, especially to get back at him for little stuff. >:D
PS/ It's not cancer or troll aids. The doctor says it's nothing to worry about.
PSS/ I still like to poke him there every once in a long while, especially to get back at him for little stuff. >:D

I'll go with parasitic twin.
http://upload.wikimedia.org/wikipedia/commons/f/f0/Slide7ooo.JPG
Looking at these diagrams, does it seem to you like the cricoid cartilage (near the bottom of the neck in both images)? The Adam's apple is more than just one blob of cartilage, it's two, but often only the top one - the thyroid cartilage - is easy to see and the bottom one - the cricoid cartilage - is difficult to see because it's smaller and set at less of an angle to the neck. My guess would be that in your boyfriend's case the cricoid cartilage is either slightly larger than normal or set at more of an angle than normal. It's not anything to worry about, in any case.
I'm no doctor though :P
You said his doctor touches it, so he or she must know it's there so it can't be anything too bad.
Search "small goiter" and see if it looks like that.
It feels similar to the cartilage you would find in your nose. It's the size of the end of your little finger and it's directly under the skin. (Almost like an implant of some kind.) It's not smooth and round, but has a jagged shape to it, it's hard to explain.