You need not worry much about the lump. Its probably lymph node enlargement. Children don't get cancer most of the times as elders do. 95% of the chance is it will be not cancer. Biopsy
will come mostly nonspecific lymphadenitis
. It could be due to infections of head, mouth, head lice
I will be happy to answer any further queries in this regard.
Dr. Balaji Chinnasami, MD
Assistant Professor- Pediatrics