Welcome to health care magic.
1.The description of the lesion suggest
lipoma ( painless hard lump ).Other possibilities
lymph nodal enlargement, bony out growth ( can be excluder with a lateral x-ray chest)
2.But need to confirm with an easy and cheap investigation
ultrasound of the lesion to find out the nature of the lesion, its sours and extensions.
3.An FNAC - to know the nature of the cells in the lump.
4.Depending on the findings - if its not symptomatic, suggest you to monitor the lesion. If any discomfort you can get it excised.
5.Suggest you not to press or scratch the lump as possibilities of infection are there. Good luck.
Hope i have answered your query.
Any thing to ask do not hesitate. Thank you.