Hi and welcome to HCM.
It is hard to say without seeing and palpating it.
In most cases it is benign. Usually lipoma, atheroma
, fiibroma or traumatic haematoma
, swollen lymoh node. If it is soft and painless it is probably lipoma. If it is painful and there is redness
of skin above it it should be evaluated by biopsy
or cytologic puncture. Malignancies have more intensive symtpoms and you shouldnt be worried. Wish you good health.