Swollen golf ball sized lump on back of daughters neck. right below hairline. center...not off center.

Prominent vertebrae: In that location it would most likely be the dorsal or back extension of a spinal vertebrae. These can be quite noticeable in some kids depending on how they are built, and do not necessarily mean anything bad. If it bothers her or you, have her doc look at it.

Needs exam: There are limited diagnoses related to a midline mass over the cervical spine and appearance, symptoms and onset are all helpful in making a diagnosis. A lipoma is a.benign fatty tumor and not uncommon, but other possibilities would include dermoid cyst or myelocele, or if red and painful, an abscess can occur anywhere. Please have this evaluated.