Thank you for your query at DoctorSpring.com
I can understand your concern.
Yes will all the blood parameters being normal, and no other similar swellings elsewhere in the body, this isolated lymph node can be safely ignored. A lot of times some lymph nodes either due to prior infection or reactive lymphadenitis get bigger, and even on healing of the infection, the swelling does not go.
Also no biopsy is required in your case.
Please do not worry.
Let me know if i can help you further,