wow, i just made an account here to say how much this post has helped me. i cough up these things daily like another poster here, doing a number on my self-esteem, and i've been looking up what could be wrong with my for years. these pictures are exactly like mine, including the little concave part. i've had scans and lots of stuff, but now, finally, know what's wrong with me and can tell a doctor. i'm so happy and grateful! thank you for sharing this information and photos!