I Have a Neck Mass/fat Deposit That Resembles a Goitre. Will Liposuction Solve This? (photo)

I am afraid your problem has no techinical solution; you mentioned ultrasound, ok, what about your TSH, T4 and T3 levels in blood? you look a lot like haveing goitre.

Liposuction can be a good option for removing the soft, fatty mass you describe on your neck, especially since it's been confirmed that your thyroid is normal. Liposuction works by suctioning out excess fat, which may help reduce the appearance of this mass. Given that the size changes with your weight, targeting the fat directly could provide noticeable improvement.
However, if there’s any skin laxity or the mass has been present for a long time, additional skin-tightening procedures may be needed for optimal results. Consulting with a board-certified plastic surgeon is the best step to evaluate whether liposuction is suitable for your specific case.

Your neck mass is not apparent in some of your photographic angles, which indicates it may be relatively thin. Ultrasound was negative for goiter, however, thyroid function tests may be helpful in your pre-op work up. Liposuction with micro canulas will improve your contour.Look for a board certified plastic surgeon, experienced in micro facial liposuction.Yours,Jon M. Grazer, MD, MPH, FACSPlastic SurgeryNewport Beach, CA

Liposuction may be reasonable in your case pending an exam.  I
would search for the board certified plastic surgeon who you feel is
most likely to give you the best results and who performs hundreds of
these procedures each year. I would look at patient reviews as well as
before and after photos on that surgeon's website.Kenneth Hughes, MDLos Angeles, CA

For the picture it looks as though you do have some excess subcutaneous fat. And in person examination would be necessary to substantiate this. If it's the case than it can be treated with liposuction probably just with local anesthesia.

Liposuction is commonly performed for fatty deposits of the neck and jowls. This can often be done under local anesthesia with or without IV sedation. The recovery is easy and can be readily performed as an outpatient. If this fullness of the neck is truly just a fatty deposit then liposuction may be an alternative for you. For the best results seek the consultation of a plastic
surgeon certified by the American Board of Plastic Surgery. They have a website
listing all the certified plastic surgeons. Members of the American Society of
Aesthetic Plastic Surgery will all be board certified in plastic surgery and
have demonstrated an interest and competence in cosmetic plastic surgery as
well.