What Does An Indentation On The Skull Indicate?

Hi, I have a ridge that has formed in the top of my skull. It is approximately 3 - 3.5 inches long. It is like my skull is separating. the ridge is as wide as my pinkie finger, but not very deep. Just shallow enough that I have been touching it a lot and wondering what is going on. I had thyroid cancer surgery and radioactive iodine; so, now i get concerned with any weird thing as there have been more side effects than anticipated. I also have consistently had drainage in my left ear whereby white stuff forms like after I wash my hair, the shampoo sits there. The only thing is that is happens every day that stuff gathers there. I don t know if this is another weird symptom or sign of something I wouldn t normally go to a doctor for. Typically you hear of people have wax in their ear, but that is not what this is. I think I mentioned it to my otorlaryngologist and he didn t make a fuss about it.