What could a lump on my back the size of golf ball next to spine be?

It's important to have any new or concerning lumps or bumps on your body evaluated by a healthcare professional, especially if they are located near the spine. While it's not possible to provide a definitive diagnosis without an in-person examination, here are a few possibilities for what the lump could be:

1. Lipoma: Lipomas are benign, fatty tumors that can grow anywhere in the body, including the back. They are usually soft, movable, and painless.

2. Sebaceous cyst: Sebaceous cysts are noncancerous growths that develop from oil glands in the skin. They can appear on the back and may feel like a firm, round lump under the skin.

3. Muscle knot or strain: If you have recently experienced any back pain or muscle strain, it's possible that the lump could be a knot or spasm in the muscles.

4. Swollen lymph node: Lymph nodes are small, bean-shaped structures that play a role in the body's immune system. When they become swollen, they can sometimes be felt as lumps under the skin.

5. Spinal tumor: While less common, it's also possible that the lump could be a tumor that has developed on or near the spine.

It's important to seek medical advice as soon as possible to get an accurate diagnosis and appropriate treatment for the lump. The healthcare professional can perform tests such as a physical examination, imaging studies, or a biopsy to determine the exact cause of the lump and recommend the best course of action.