Is a lump on end of clavicle bone normal?

Maybe, maybe not: It could be benign, such as result of old trauma or arthritis of the joint at the end. If it is growing or painful, see your primary doctor for a check.

Osteoarthritis AC jo: It is not normal, however you may have a very common codition that is osteoarthritis of the acromioclavicular joint and that condition will give the lump you are reffering to.

Simple vs serious: Our bodies always have things that grow and change. Skin, fat, muscle, lymph nodes, bones, can change shape, get larger, more prominent due to many factors. The vast majority are not cancer but simply unusual growths like fatty tumors, cysts, skin tags, moles, etc. Most cause no symptoms and can be watched. If they cause symptoms or change colors, bleed, bruise or hurt, then see your doctor.