Brief Answer:
you need to get clinically examined and investigated thoroughly ..

Detailed Answer:
Hello XXXXXXX fye, Welcome to HCM,

I've gone through your query and understand your concern,

Now please let me know a few details, so that I can guide you more specifically,

How is the swelling, is it soft/boggy/firm/hard ?

Is there any redness/skin discoloration visible over it ?

Have you got any recent history of infection/influenza/sore throat in past few months ?

How did the swelling start, was it all of a sudden ?

How does it regress ?

Most importantly, was there any confirmatory investigations done to show that it's lymph node and not something else ?

If possible, please take a snapshot and upload it here at the reports section so that I can get closer look at it please ?

Well the mono 10 years back is not likely to be associated with it but there are several other possible causes for it(mostly infectious), which is why all those answers are necessary to know and at the same time it's also necessary to run a few investigations i.e. CBC, CRP, Ultrasound of the swelling to determine the nature of it..

Since you've mentioned that you've visited a doctor already, please let me know if any investigations or medications have you undertaken already for this ..

Awaiting for your response..

Take Care
Kind Regards

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