What can this mean... Indeterminate uptake in the medistinial/ hilar nodes in a colon cancer pt? This was noted from a pet scan. Can it mean mets?

Indeterminate. Metastatic cancer causes increased metabolic activity in lymph nodes. Inflammation and othe conditions can also do that, but not as much. Indeterminate uptake means that the uptake is more than normal, but not so high as to make cancer virtually certain. The uptake is in the range where it could be cancer, but is more likely non-cancer. Hence, indeterminate.
Probably nothing. If one has had colon cancer, it is important to know the stage at which the tumor was resected. Where there positive lymph nodes in the mesentery and was adjuvant chemo needed to prevent possible recurrence. Are tumor markers elevated ie CEA, Ca19.9. Indeterminate uptake probable means nothing and mediastinal nodes would not be the site for colon to spread.