Growth on neck its itchy???

[grumpybear0810]

I have a male 9 month old kitten that we rescued from my boyfriends work. When we brought him home I noticed on the side of him head/neck he had a small bump over the past two months it has grown. When I first took him to the vet he said not to worry about it could just be a small growth wait and see. It has never seemed to bother him before but the past few days he has been itching at it.
Facts to know
*He is not nuetered
* up to date on his shots
*does not have a fever
*eats fine
*feels slighlty liquidy when pressed on
*shows no discomfort besides the scratching
*had clamydia last month both him and other cat were treated and recovered fine
If anyone knows what this may be or has an information they think will be helpful please reply!