For how long you have the lump?
What's the size of the lump?
Is it easily noticeable with eyes?
Have you noticed some other symptoms like frequent urination, excessive thirst and extreme hunger, along with fatigue and losing weight?

i remember feeling a lump a few years ago now, maybe 3-4. my mum felt it too but we didnt think it was anything serious and i forgot about it. but it was tiny then, smaller than baby pea size width, and hardly stuck out. plus my jaw was normal back then. now it is visible especially if i open my mouth. i noticed it around christmas time along with the jaw asymmetry.
its hard to say how big because its not a round ball, its on the corner of my jaw and goes under..making the bone that side much thicker underneath..and the thickness goes right up my jaw. the lumpy bit that sticks out most is probly 2 by 1.5cm width but doesn't stick out very much, more grows into the bone.
i only noticed my weird jaw at xmas but it must have been 'growing' for a long time. this is very much noticeable...both sides of my face look completely different now. esp with the eye thing, its very upsetting and embarrassing. im so ugly now. when i first noticed it i didnt want to go out or anything because if you look at my face properly you'll see it but i try to ignore it.

frequent urination yes. but i had abdominal/pelvic surgery and had a metal plate and pins put in so im not sure if its because of that..it seemed to start straight after that..when i was first starting to walk again. i definitely didn't have it before.
no excessive thirst.
no 'excessive' hunger, but ive been forcing myself to eat alot so i don't really let myself get all that hungry. i just eat when i think i should, like set meal times and try to eat as much as i can but i seem to get full up quicker and stay full for longer.like my stomachs bloated after eating. i guess trying to eat as much as i can could be excessive hunger but its more a conscious thing rather than physiological hunger.

i didnt mention before but ive also found a lump in my throat above my adams apple/voicebox. on the left side,i can only feel half of it but i can move it around a bit by pushing on my neck and it makes a popping sound if i push it a certain way. if i push into the right side of my neck (where i can't feel it normally) it pushes out the left side. if i push onit from the left some of it appears on the right side. its hard and doesnt hurt at all. but sometimes (rarely) i have feeling like ive swallowed something thats got stuck in my throat, faintly, on the right side where i imagine the bottom-right edge of this thing is. and im getting mild sore throats more than i think is normal now.
this is seriously getting to the hypochondriac level now i know but i am not imagining any of these things...wish i was! Thanks for the reply

its mumps mate dont worry, see your gp

have your dentist or doctor get a scan of your face/jaw or the whole head. It could be a rare deformity of the jaw which also known as ameloblastoma. I am speaking from experience. One day i felt what i thought was a tooth ache. I left it alone for a couple days until the pain and swelling subsided. Luckily I had already set up an appointment with my dentist for regular cleaning. As she was checking my gums and jaw, she notice something hard in the back of my mouth. She immediately ask me to get a scan/xray of my face. She had asked me to go to a nuerologist as soon as I can so that they check it out. I went as soon as I can. They had taken a piece of tissue for biopsy and got the result after 1 week. I got the news- it's ameloblastoma, not a cancerous tumor but very aggresive in terms of growth. If I had not found out about it- my left jaw would have been a size of a coconut in less than 6 months. I know have a titanium plate jaw (half) and tumor free. Only set back is that there's a part of my left face/chin that is numb. Please go see your doctor or dentist about it.

Hello. I see you wrote your question over a year ago. I just arrived -- I would like to answer and I hope you will be able to see my answer somehow. No I do not think you have cancer at all. You are not really healthy because of your health problems so see a doctor of course and follow the doctors recommendations. Not mine but I do have some ideas. Lay flat on the floor. That will help to align everything. Food is not really a big deal but nice if you are your target weight. Your teeth are causing the vision thing. Yes and you could have some removed to stop it from blurring. That is what I think only. Talk to a doctor about it too. Good that you have probably resolved alot of this yourself by now.