Thank you for your query.
I can understand your concern on hearing all these diagnoses. As you mention that your son has some sores on his chin they can be the cause of enlarged lymph
nodes in the neck which you are noticing as a lump. You are doing the right thing by consulting your doctor who will examine him thoroughly and do the following:
1. Prescribe medicines according to his examination.
2. Do a work-up to confirm his diagnosis and exclude the other possible causes.
I hope I have answered your query to your satisfaction.
Wishing your son an early recovery.