It would be better to do an USG and see if any sonological features of malignancy is there in the node. Also can see if other nodes are there in any of the other neck node stations. Consider doing blood tests like
complete blood count, LDH,
uric acid ,
electrolytes. Also see if you have any other relevant symptoms which you should notify treating doctor. Based on the USG findings, can decide if an FNA or biopsy would be apt.
Also there is possibility that this could just be an infective node. Anyway let the USG happen.
Next Steps
USG neck, blood tests as mentioned