Sorry for delayed post!
Lump that has a history of a slowly growing process for several years and usually do not cause any real discomfort, just mild tenderness occasionally, is known as lipoma.
It is a benign tumor composed of mature fat cells.
This lump can very in diameter from 2-10 cm and usual location is back and shoulders.
Men often develop more than one lipoma.
These aren't life-threatening lumps (surgically removed).