What Causes Lump In Solar Plexus And Stabbing Pain In Chest?

Hello, I have a lump in my solar plexus, if you follow the middle of the rib cage down where it ends I have a lump abouts the size of a chestnut. It is not visable but causes slight pain if I press it. I have been getting sharp stabbing pains it my chest that travel up to the side of my jaw. I don t know if they are linked or if I need to see a doctor.