Mary,

I'm not a doctor, and not familiar with your friends case other than what is said, but Penn State surgeons have become the worlds first to test a glowing dye for cancerous lymph nodes. There are other fluorescence lights, and dyes used during surgery, but not sure if the would applicable for lymph nodes other then what I mentioned. Usually they remove the lymph nodes by a lymph chain or levels like they do in neck dissections. I believe called en bloc, meaning altogether at the same time, so there is no cancer seeding also.

During surgery, frozen sections are often obtained during surgery to get clear margins, but all the biopsied tissue are sent for further analysis, which can take several days or even a week. That has happened to me, surgery was clear, but the final biopsy showed cancer cells, and other negative features such as perneural and lymphovascular invasion.

No scana are 100% accurate, or can prove cancer, only a biopsy can, but Pet scans are pretty accurate in the 90% range for certain scanning aspects, and depending on location, which can go as small as 5mm. Maybe your friends tumor was too small or other things were done that can effect a Pet scan highlight (SUV). Scans are also only as good as the person reviewing them, and sometimes patients even doctors send them out for further review.

There are about 300 lymph nodes in the head and neck, most which are microscopic, and everyone is different in the amount and location of such. As far as your friend, the cancer could have already been there microscopically or the cancer found other pathways to travel, and just taking a guess. I know, I had cancer 7 times! In the primary tonsil, and 7 tines were in and out of the lymoh nodes. After my radical neck dissection, my 3rd cancer, cancer was found in the neck muscle too, and later surgeries in lymph nodes in areas where I had a radical neck dissection in level ll-V, and other times in tissue that were not lymph nodes, and basically free roaming cancer.

A negative feature with neck dissections is it disrupts the pathway such as the lymph flow, so cancer can find alternate pathways if cancer was to return or was reminiscent lets say to the primary. Basically, cancer can go anywhere, but it usually has a predictive pattern with the lymph flow, and reason for neck dissections as to control the gateway to distant metastases. As I once heard, besides the primary, controlling the nodes is the key to survival.

I hope this helps
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