A lump or mass in the neck can be from many causes. Most commonly it is from an infection, such as chronic tonsillitis or an infected tooth. An exact diagnosis may be difficult without a biopsy. Young children often have lymph nodes in their neck.
Masses are worrisome when they persist, are multiple, are hard or fixed.
A needle biopsy is performed by inserting a fine needle into the mass and using negative pressure to obtain a few cells for the pathologist to look at. An open biopsy, as shown below, is much more accurate, but it is difficult to do and may put various structures at risk. In the patient shown below, a needle biopsy indicated that the neck mass was from a congenital cyst. However, upon exploration, infected lymph nodes were found.