How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • Go back-and-forth until satisfied
    Rate the answer you receive.
Ask Dr. P. Jyoti Your Own Question
Dr. P. Jyoti
Dr. P. Jyoti, Doctor
Category: Oncology
Satisfied Customers: 18277
Experience:  MD specialist in head and neck cancer surgery and therapy
Type Your Oncology Question Here...
Dr. P. Jyoti is online now

If a pre chemo PET-CT doesn’t show lymph node involvement

This answer was rated:

If a pre chemo PET-CT doesn’t show lymph node involvement and surgery is successful in removing the, now tiny, original tumour why would 1/27 lymph nodes test positive in pathology?

Biopsy is the final diagnostic tool for detecting involvement of lymph nodes. PET CT may sometimes fail to detect positive lymph nodes but biopsies will catch such undetected nodes also.

Customer: replied 13 days ago.
I understand that lymph activity may be too small to be picked up by PET-CT initially and pathology during/after surgery Is most reliable.
If the patient responded extremely well to chemo, with tumour markers close to 0 at time of surgery, the residual malignancy being 2mm (from an original 24mm) and the rest fibrotic, a 3mm R0 margin and no perineural invasion it seems as though the lymphs should have most likely been clear.
Could it have simply been the closest lymph to the remaining malignancy and a direct invasion?

It could be the nearest node, but not necessarily so. This is most likely a node in which the last remaining cells were not wiped out despite this being so in other areas. That is why surgeons do lymph node resection always in case of large tumours.

Dr. P. Jyoti and other Oncology Specialists are ready to help you