My 4 yr kid have enlarged movable lymph node (post cervical) frm abt 7 months after pneumonia. recently i noticed another one below- not sure about its duration. shld we go for surgry to diagnose?

Yes : It is definetly cause for concern having persistent lymphadenopathy.

Depends on variables: Posterior cervical lymph nodes are rarely if ever involved in response to a pneumonia.They are more likely reacting to throat or superficial skin issues in the region. They receive plenty of attention since they are easy to find. If they have gone through cycles of increasing/decreasing in size & remain peanut sized or smaller, they are likely normal.If persistently large, biopsy may be necessary.