Even if you can't find something, a couple other options:
1) Do something ENT-related with the dept of surgery at your school. Lots of endocrine and surg onc stuff would overlap a bit. If you have a derm department, someone there might be doing some head and neck skin cancer research. You may have to be a little creative.
2) Do a research year between M3 and M4. Ideally, find a spot at a bigger program with lots of well known faculty and a program where you might be interested in ultimately matching. I find myself recommending this option to underclassmen more and more lately and I think it can be a very wise move for certain people. You could simultaneously get a ton of publications, get some good letters from well-known people who will actually know you, and if you work hard enough and are well liked, maybe even solidify yourself a spot at that program (definitely not guaranteed, but either way you still get pubs and letters). Lots of people on the trail this year seemed to have done research years, either on their own or as part of their school's requirements.
