If you have not had a complete head and neck work up including an MRI of both areas, your doctors have not been thorough in their pursuit of things. A carcinoma in situ, can indeed be on the surface and not have progressed to other areas, but the only way to know for sure is to do the complete diagnostic protocol, including the MRI's. Once you have done that you should feel more at ease with a radiologists opinion added to things. It sounds like the surgeon has already removed the suspect tissue, and if so, the pathologist should be able to say to you that all the margins were cancer free, and he should state so in his written report. That means that the surgeon did indeed get all of that particular cancer. But whether that cancer threw out a node metastasis......he can't tell you with out the scans.