One of the problems with this, even for surgeons who've been looking at this a lot, is you can't see the cancer, especially when it's hidden below the surface.
其中一个问题是， 即使对于外科医生，尽管他已经看过很多这样的病例， 你看不到这个肿瘤， 特别是当它隐藏在深处的时候。