I have a lump in my back what could it be?

Many possibilities: A "lump in my back" can be due to a number of things including a lipoma (fatty mass), sebaceous cyst, lymphoma, tumor (muscle, skin, or other tumor), keloid, bony prominence, or other causes. See your doctor for a more definite diagnosis and possible treatment plan.

Remove new lumps: New lumps on the back may be surface growths or dermal (under the epidermis of the skin but above the fat) such as cysts, keratoses, moles , fatty growths (lipomas) or muscular growths. There truly are a myriad of possibilities. Either a dermatologist, surgeon , or your primary care doctor should examine you but in order to prove it's not malignant it is wise to remove new lesions for a biopsy.